notifications module - POC

apps/client/src/features/space/components/multi-member-select.tsx

@@ -26,9 +26,6 @@ const renderMultiSelectOption: MultiSelectProps["renderOption"] = ({
     {option["type"] === "group" && <IconGroupCircle />}
     <div>
       <Text size="sm" lineClamp={1}>{option.label}</Text>
-      {option["type"] === "user" && option["email"] && (
-        <Text size="xs" c="dimmed" lineClamp={1}>{option["email"]}</Text>
-      )}
     </div>
   </Group>
 );
@@ -50,7 +47,6 @@ export function MultiMemberSelect({ onChange }: MultiMemberSelectProps) {
       const userItems = suggestion?.users.map((user: IUser) => ({
         value: `user-${user.id}`,
         label: user.name,
-        email: user.email,
         avatarUrl: user.avatarUrl,
         type: "user",
       }));

apps/server/src/core/core.module.ts

@@ -16,6 +16,7 @@ import { GroupModule } from './group/group.module';
 import { CaslModule } from './casl/casl.module';
 import { DomainMiddleware } from '../common/middlewares/domain.middleware';
 import { ShareModule } from './share/share.module';
+import { NotificationModule } from './notification/notification.module';
 
 @Module({
   imports: [
@@ -30,6 +31,7 @@ import { ShareModule } from './share/share.module';
     GroupModule,
     CaslModule,
     ShareModule,
+    NotificationModule,
   ],
 })
 export class CoreModule implements NestModule {

apps/server/src/core/notification/INTEGRATION_GUIDE.md

@@ -0,0 +1,276 @@
+# Notification System Integration Guide
+
+This guide explains how to integrate the notification system into existing services.
+
+## Quick Start
+
+### 1. Import NotificationService
+
+```typescript
+import { NotificationService } from '@/core/notification/services/notification.service';
+import { NotificationType } from '@/core/notification/types/notification.types';
+```
+
+### 2. Inject the Service
+
+```typescript
+constructor(
+  private readonly notificationService: NotificationService,
+  // ... other dependencies
+) {}
+```
+
+### 3. Create Notifications
+
+```typescript
+// Example: Notify user when mentioned in a comment
+await this.notificationService.createNotification({
+  workspaceId: workspace.id,
+  recipientId: mentionedUserId,
+  actorId: currentUser.id,
+  type: NotificationType.MENTION_IN_COMMENT,
+  entityType: 'comment',
+  entityId: comment.id,
+  context: {
+    pageId: page.id,
+    pageTitle: page.title,
+    commentText: comment.content.substring(0, 100),
+    actorName: currentUser.name,
+    threadRootId: comment.parentCommentId || comment.id,
+  },
+  priority: NotificationPriority.HIGH,
+  groupKey: `comment:${comment.id}:mentions`,
+  deduplicationKey: `mention:${mentionedUserId}:comment:${comment.id}`,
+});
+```
+
+## Integration Examples
+
+### CommentService Integration
+
+```typescript
+// In comment.service.ts
+import { NotificationService } from '@/core/notification/services/notification.service';
+import { NotificationType, NotificationPriority } from '@/core/notification/types/notification.types';
+
+export class CommentService {
+  constructor(
+    private readonly notificationService: NotificationService,
+    // ... other dependencies
+  ) {}
+
+  async createComment(dto: CreateCommentDto, user: User): Promise<Comment> {
+    const comment = await this.commentRepo.create(dto);
+    
+    // Notify page owner about new comment
+    if (page.creatorId !== user.id) {
+      await this.notificationService.createNotification({
+        workspaceId: workspace.id,
+        recipientId: page.creatorId,
+        actorId: user.id,
+        type: NotificationType.COMMENT_ON_PAGE,
+        entityType: 'comment',
+        entityId: comment.id,
+        context: {
+          pageId: page.id,
+          pageTitle: page.title,
+          commentText: comment.content.substring(0, 100),
+          actorName: user.name,
+        },
+        groupKey: `page:${page.id}:comments`,
+      });
+    }
+    
+    // Check for mentions and notify mentioned users
+    const mentionedUserIds = this.extractMentions(comment.content);
+    for (const mentionedUserId of mentionedUserIds) {
+      await this.notificationService.createNotification({
+        workspaceId: workspace.id,
+        recipientId: mentionedUserId,
+        actorId: user.id,
+        type: NotificationType.MENTION_IN_COMMENT,
+        entityType: 'comment',
+        entityId: comment.id,
+        context: {
+          pageId: page.id,
+          pageTitle: page.title,
+          commentText: comment.content.substring(0, 100),
+          actorName: user.name,
+          threadRootId: comment.parentCommentId || comment.id,
+        },
+        priority: NotificationPriority.HIGH,
+        deduplicationKey: `mention:${mentionedUserId}:comment:${comment.id}`,
+      });
+    }
+    
+    return comment;
+  }
+  
+  async resolveComment(commentId: string, user: User): Promise<void> {
+    const comment = await this.commentRepo.findById(commentId);
+    
+    // Notify comment creator that their comment was resolved
+    if (comment.creatorId !== user.id) {
+      await this.notificationService.createNotification({
+        workspaceId: workspace.id,
+        recipientId: comment.creatorId,
+        actorId: user.id,
+        type: NotificationType.COMMENT_RESOLVED,
+        entityType: 'comment',
+        entityId: comment.id,
+        context: {
+          pageId: page.id,
+          pageTitle: page.title,
+          resolverName: user.name,
+        },
+      });
+    }
+  }
+}
+```
+
+### PageService Integration
+
+```typescript
+// In page.service.ts
+async exportPage(pageId: string, format: string, user: User): Promise<void> {
+  // Start export process...
+  
+  // When export is complete
+  await this.notificationService.createNotification({
+    workspaceId: workspace.id,
+    recipientId: user.id,
+    actorId: user.id, // System notification
+    type: NotificationType.EXPORT_COMPLETED,
+    entityType: 'page',
+    entityId: pageId,
+    context: {
+      pageTitle: page.title,
+      exportFormat: format,
+      downloadUrl: exportUrl,
+      expiresAt: expiryDate.toISOString(),
+    },
+    priority: NotificationPriority.LOW,
+  });
+}
+
+async updatePage(pageId: string, content: any, user: User): Promise<void> {
+  // Check for mentions in the content
+  const mentionedUserIds = this.extractMentionsFromContent(content);
+  
+  for (const mentionedUserId of mentionedUserIds) {
+    await this.notificationService.createNotification({
+      workspaceId: workspace.id,
+      recipientId: mentionedUserId,
+      actorId: user.id,
+      type: NotificationType.MENTION_IN_PAGE,
+      entityType: 'page',
+      entityId: pageId,
+      context: {
+        pageTitle: page.title,
+        actorName: user.name,
+        mentionContext: this.extractMentionContext(content, mentionedUserId),
+      },
+      priority: NotificationPriority.HIGH,
+      deduplicationKey: `mention:${mentionedUserId}:page:${pageId}:${Date.now()}`,
+    });
+  }
+}
+```
+
+### WsGateway Integration for Real-time Notifications
+
+The notification system automatically sends real-time updates through WebSocket. The WsGateway is already injected into NotificationDeliveryService.
+
+```typescript
+// In ws.gateway.ts - Already implemented in NotificationDeliveryService
+async sendNotificationToUser(userId: string, notification: any): Promise<void> {
+  const userSockets = await this.getUserSockets(userId);
+  
+  for (const socketId of userSockets) {
+    this.server.to(socketId).emit('notification:new', {
+      id: notification.id,
+      type: notification.type,
+      entityType: notification.entityType,
+      entityId: notification.entityId,
+      context: notification.context,
+      createdAt: notification.createdAt,
+      readAt: notification.readAt,
+    });
+  }
+}
+```
+
+## Notification Types
+
+Available notification types:
+- `MENTION_IN_PAGE` - User mentioned in a page
+- `MENTION_IN_COMMENT` - User mentioned in a comment
+- `COMMENT_ON_PAGE` - New comment on user's page
+- `COMMENT_IN_THREAD` - Reply to user's comment
+- `COMMENT_RESOLVED` - User's comment was resolved
+- `EXPORT_COMPLETED` - Export job finished
+
+## Best Practices
+
+1. **Use Deduplication Keys**: Prevent duplicate notifications for the same event
+   ```typescript
+   deduplicationKey: `mention:${userId}:comment:${commentId}`
+   ```
+
+2. **Set Appropriate Priority**: 
+   - HIGH: Mentions, direct replies
+   - NORMAL: Comments on owned content
+   - LOW: System notifications, exports
+
+3. **Group Related Notifications**: Use groupKey for notifications that should be batched
+   ```typescript
+   groupKey: `page:${pageId}:comments`
+   ```
+
+4. **Include Relevant Context**: Provide enough information for email templates
+   ```typescript
+   context: {
+     pageId: page.id,
+     pageTitle: page.title,
+     actorName: user.name,
+     // ... other relevant data
+   }
+   ```
+
+5. **Check User Preferences**: The notification service automatically checks user preferences, but you can pre-check if needed:
+   ```typescript
+   const preferences = await notificationPreferenceService.getUserPreferences(userId, workspaceId);
+   if (preferences.emailEnabled) {
+     // Create notification
+   }
+   ```
+
+## Testing Notifications
+
+Use the test endpoint to send test notifications:
+
+```bash
+curl -X POST http://localhost:3000/api/notifications/test \
+  -H "Authorization: Bearer YOUR_TOKEN" \
+  -H "Content-Type: application/json" \
+  -d '{
+    "type": "MENTION_IN_PAGE",
+    "recipientId": "USER_ID"
+  }'
+```
+
+## Email Templates
+
+Email templates are located in `/core/notification/templates/`. To add a new template:
+
+1. Create a new React component in the templates directory
+2. Update the email sending logic in NotificationDeliveryService
+3. Test the template using the React Email preview server
+
+## Monitoring
+
+Monitor notification delivery through logs:
+- Check for `NotificationService` logs for creation events
+- Check for `NotificationDeliveryService` logs for delivery status
+- Check for `NotificationBatchProcessor` logs for batch processing

apps/server/src/core/notification/controllers/notification.controller.ts

@@ -0,0 +1,122 @@
+import {
+  Controller,
+  Get,
+  Post,
+  Put,
+  Body,
+  Param,
+  Query,
+  UseGuards,
+} from '@nestjs/common';
+import { JwtAuthGuard } from '../../../common/guards/jwt-auth.guard';
+import { AuthUser } from '../../../common/decorators/auth-user.decorator';
+import { AuthWorkspace } from '../../../common/decorators/auth-workspace.decorator';
+import { User, Workspace } from '@docmost/db/types/entity.types';
+import { NotificationService } from '../services/notification.service';
+import { NotificationPreferenceService } from '../services/notification-preference.service';
+import { GetNotificationsDto } from '../dto/get-notifications.dto';
+import { UpdateNotificationPreferencesDto } from '../dto/update-preference.dto';
+import { NotificationType } from '../types/notification.types';
+
+@Controller('notifications')
+@UseGuards(JwtAuthGuard)
+export class NotificationController {
+  constructor(
+    private readonly notificationService: NotificationService,
+    private readonly preferenceService: NotificationPreferenceService,
+  ) {}
+
+  @Get()
+  async getNotifications(
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+    @Query() query: GetNotificationsDto,
+  ) {
+    const { grouped = true, status, limit = 20, offset = 0 } = query;
+
+    if (grouped) {
+      return await this.notificationService.getGroupedNotifications(
+        user.id,
+        workspace.id,
+        { status, limit, offset },
+      );
+    }
+
+    return await this.notificationService.getNotifications(
+      user.id,
+      workspace.id,
+      { status, limit, offset },
+    );
+  }
+
+  @Get('unread-count')
+  async getUnreadCount(@AuthUser() user: User) {
+    const count = await this.notificationService.getUnreadCount(user.id);
+    return { count };
+  }
+
+  @Post(':id/read')
+  async markAsRead(
+    @AuthUser() user: User,
+    @Param('id') notificationId: string,
+  ) {
+    await this.notificationService.markAsRead(notificationId, user.id);
+    return { success: true };
+  }
+
+  @Post('mark-all-read')
+  async markAllAsRead(@AuthUser() user: User) {
+    await this.notificationService.markAllAsRead(user.id);
+    return { success: true };
+  }
+
+  @Get('preferences')
+  async getPreferences(
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+  ) {
+    return await this.preferenceService.getUserPreferences(
+      user.id,
+      workspace.id,
+    );
+  }
+
+  @Put('preferences')
+  async updatePreferences(
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+    @Body() dto: UpdateNotificationPreferencesDto,
+  ) {
+    return await this.preferenceService.updateUserPreferences(
+      user.id,
+      workspace.id,
+      dto,
+    );
+  }
+
+  @Get('preferences/stats')
+  async getNotificationStats(
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+  ) {
+    return await this.preferenceService.getNotificationStats(
+      user.id,
+      workspace.id,
+    );
+  }
+
+  @Post('test')
+  async sendTestNotification(
+    @AuthUser() user: User,
+    @AuthWorkspace() workspace: Workspace,
+    @Body() dto: { type: NotificationType },
+  ) {
+    await this.notificationService.createTestNotification(
+      user.id,
+      workspace.id,
+      dto.type,
+    );
+
+    return { success: true, message: 'Test notification sent' };
+  }
+}

apps/server/src/core/notification/dto/create-notification.dto.ts

@@ -0,0 +1,58 @@
+import {
+  IsEnum,
+  IsNotEmpty,
+  IsObject,
+  IsOptional,
+  IsString,
+  IsUUID,
+} from 'class-validator';
+import {
+  NotificationType,
+  NotificationPriority,
+} from '../types/notification.types';
+
+export class CreateNotificationDto {
+  @IsUUID()
+  @IsNotEmpty()
+  workspaceId: string;
+
+  @IsUUID()
+  @IsNotEmpty()
+  recipientId: string;
+
+  @IsUUID()
+  @IsOptional()
+  actorId?: string;
+
+  @IsEnum(NotificationType)
+  @IsNotEmpty()
+  type: NotificationType;
+
+  @IsString()
+  @IsNotEmpty()
+  entityType: string;
+
+  @IsUUID()
+  @IsNotEmpty()
+  entityId: string;
+
+  @IsObject()
+  @IsNotEmpty()
+  context: Record<string, any>;
+
+  @IsEnum(NotificationPriority)
+  @IsOptional()
+  priority?: NotificationPriority;
+
+  @IsString()
+  @IsOptional()
+  groupKey?: string;
+
+  @IsString()
+  @IsOptional()
+  deduplicationKey?: string;
+
+  // For scheduling notifications (quiet hours, etc.)
+  @IsOptional()
+  scheduledFor?: Date;
+}

apps/server/src/core/notification/dto/get-notifications.dto.ts

@@ -0,0 +1,34 @@
+import {
+  IsEnum,
+  IsOptional,
+  IsBoolean,
+  IsNumber,
+  Min,
+  Max,
+} from 'class-validator';
+import { Transform } from 'class-transformer';
+import { NotificationStatus } from '../types/notification.types';
+
+export class GetNotificationsDto {
+  @IsEnum(NotificationStatus)
+  @IsOptional()
+  status?: NotificationStatus;
+
+  @IsBoolean()
+  @Transform(({ value }) => value === 'true' || value === true)
+  @IsOptional()
+  grouped?: boolean = true;
+
+  @IsNumber()
+  @Transform(({ value }) => parseInt(value, 10))
+  @Min(1)
+  @Max(100)
+  @IsOptional()
+  limit?: number = 20;
+
+  @IsNumber()
+  @Transform(({ value }) => parseInt(value, 10))
+  @Min(0)
+  @IsOptional()
+  offset?: number = 0;
+}

apps/server/src/core/notification/dto/update-preference.dto.ts

@@ -0,0 +1,75 @@
+import {
+  IsBoolean,
+  IsEnum,
+  IsNumber,
+  IsObject,
+  IsOptional,
+  IsString,
+  Max,
+  Min,
+  Matches,
+  IsArray,
+} from 'class-validator';
+import {
+  EmailFrequency,
+  NotificationTypeSettings,
+} from '../types/notification.types';
+
+export class UpdateNotificationPreferencesDto {
+  @IsBoolean()
+  @IsOptional()
+  emailEnabled?: boolean;
+
+  @IsBoolean()
+  @IsOptional()
+  inAppEnabled?: boolean;
+
+  @IsObject()
+  @IsOptional()
+  notificationSettings?: Record<string, NotificationTypeSettings>;
+
+  @IsNumber()
+  @Min(5)
+  @Max(60)
+  @IsOptional()
+  batchWindowMinutes?: number;
+
+  @IsNumber()
+  @Min(1)
+  @Max(100)
+  @IsOptional()
+  maxBatchSize?: number;
+
+  @IsArray()
+  @IsString({ each: true })
+  @IsOptional()
+  batchTypes?: string[];
+
+  @IsEnum(EmailFrequency)
+  @IsOptional()
+  emailFrequency?: EmailFrequency;
+
+  @Matches(/^([0-1]?[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]$/)
+  @IsOptional()
+  digestTime?: string;
+
+  @IsBoolean()
+  @IsOptional()
+  quietHoursEnabled?: boolean;
+
+  @Matches(/^([0-1]?[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]$/)
+  @IsOptional()
+  quietHoursStart?: string;
+
+  @Matches(/^([0-1]?[0-9]|2[0-3]):[0-5][0-9]:[0-5][0-9]$/)
+  @IsOptional()
+  quietHoursEnd?: string;
+
+  @IsString()
+  @IsOptional()
+  timezone?: string;
+
+  @IsBoolean()
+  @IsOptional()
+  weekendNotifications?: boolean;
+}

apps/server/src/core/notification/events/notification.events.ts

@@ -0,0 +1,45 @@
+import { Notification } from '@docmost/db/types/entity.types';
+
+export class NotificationCreatedEvent {
+  constructor(
+    public readonly notification: Notification,
+    public readonly workspaceId: string,
+  ) {}
+}
+
+export class NotificationReadEvent {
+  constructor(
+    public readonly notificationId: string,
+    public readonly userId: string,
+  ) {}
+}
+
+export class NotificationAllReadEvent {
+  constructor(
+    public readonly userId: string,
+    public readonly notificationIds: string[],
+  ) {}
+}
+
+export class NotificationBatchScheduledEvent {
+  constructor(
+    public readonly batchId: string,
+    public readonly scheduledFor: Date,
+  ) {}
+}
+
+export class NotificationAggregatedEvent {
+  constructor(
+    public readonly aggregationId: string,
+    public readonly notificationIds: string[],
+  ) {}
+}
+
+// Event names as constants
+export const NOTIFICATION_EVENTS = {
+  CREATED: 'notification.created',
+  READ: 'notification.read',
+  ALL_READ: 'notification.allRead',
+  BATCH_SCHEDULED: 'notification.batchScheduled',
+  AGGREGATED: 'notification.aggregated',
+} as const;

apps/server/src/core/notification/notification.module.ts

@@ -0,0 +1,32 @@
+import { Module } from '@nestjs/common';
+import { BullModule } from '@nestjs/bullmq';
+import { NotificationService } from './services/notification.service';
+import { NotificationPreferenceService } from './services/notification-preference.service';
+import { NotificationDeduplicationService } from './services/notification-deduplication.service';
+import { NotificationDeliveryService } from './services/notification-delivery.service';
+import { NotificationBatchingService } from './services/notification-batching.service';
+import { NotificationAggregationService } from './services/notification-aggregation.service';
+import { NotificationController } from './controllers/notification.controller';
+import { NotificationBatchProcessor } from './queues/notification-batch.processor';
+import { WsModule } from '../../ws/ws.module';
+
+@Module({
+  imports: [
+    BullModule.registerQueue({
+      name: 'notification-batch',
+    }),
+    WsModule,
+  ],
+  controllers: [NotificationController],
+  providers: [
+    NotificationService,
+    NotificationPreferenceService,
+    NotificationDeduplicationService,
+    NotificationDeliveryService,
+    NotificationBatchingService,
+    NotificationAggregationService,
+    NotificationBatchProcessor,
+  ],
+  exports: [NotificationService, NotificationPreferenceService],
+})
+export class NotificationModule {}

apps/server/src/core/notification/queues/notification-batch.processor.ts

@@ -0,0 +1,70 @@
+import { Processor } from '@nestjs/bullmq';
+import { WorkerHost } from '@nestjs/bullmq';
+import { Injectable, Logger } from '@nestjs/common';
+import { Job } from 'bullmq';
+import { NotificationBatchingService } from '../services/notification-batching.service';
+
+@Processor('notification-batch')
+export class NotificationBatchProcessor extends WorkerHost {
+  private readonly logger = new Logger(NotificationBatchProcessor.name);
+
+  constructor(private readonly batchingService: NotificationBatchingService) {
+    super();
+  }
+
+  async process(job: Job<any, any, string>) {
+    if (job.name === 'process-batch') {
+      return this.processBatch(job);
+    } else if (job.name === 'check-pending-batches') {
+      return this.checkPendingBatches(job);
+    }
+  }
+
+  async processBatch(job: Job<{ batchId: string }>) {
+    this.logger.debug(`Processing notification batch: ${job.data.batchId}`);
+
+    try {
+      await this.batchingService.processBatch(job.data.batchId);
+      return { success: true, batchId: job.data.batchId };
+    } catch (error) {
+      this.logger.error(
+        `Failed to process batch ${job.data.batchId}:`,
+        error instanceof Error ? error.stack : String(error),
+      );
+      throw error;
+    }
+  }
+
+  async checkPendingBatches(job: Job) {
+    this.logger.debug('Checking for pending notification batches');
+
+    try {
+      const pendingBatches = await this.batchingService.getPendingBatches();
+
+      for (const batch of pendingBatches) {
+        // Calculate delay
+        const delay = Math.max(0, batch.scheduled_for.getTime() - Date.now());
+
+        // Add to queue with appropriate delay
+        await this.queue.add('process-batch', { batchId: batch.id }, { delay });
+
+        this.logger.debug(
+          `Scheduled batch ${batch.id} for processing in ${delay}ms`,
+        );
+      }
+
+      return { processedCount: pendingBatches.length };
+    } catch (error) {
+      this.logger.error(
+        'Failed to check pending batches:',
+        error instanceof Error ? error.stack : String(error),
+      );
+      throw error;
+    }
+  }
+
+  // Reference to the queue (injected by Bull)
+  private get queue() {
+    return (this as any).queue;
+  }
+}

apps/server/src/core/notification/services/notification-aggregation.service.ts

@@ -0,0 +1,259 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { NotificationAggregationRepo } from '@docmost/db/repos/notification/notification-aggregation.repo';
+import { NotificationRepo } from '@docmost/db/repos/notification/notification.repo';
+import { Notification, NotificationAggregation } from '@docmost/db/types/entity.types';
+import { 
+  NotificationType,
+  AggregationType,
+  AggregatedNotificationMessage,
+} from '../types/notification.types';
+
+interface AggregationRule {
+  types: NotificationType[];
+  timeWindow: number;
+  minCount: number;
+  aggregationType: 'actor_based' | 'time_based' | 'count_based';
+}
+
+@Injectable()
+export class NotificationAggregationService {
+  private readonly logger = new Logger(NotificationAggregationService.name);
+
+  private readonly aggregationRules: Map<NotificationType, AggregationRule> =
+    new Map([
+      [
+        NotificationType.COMMENT_ON_PAGE,
+        {
+          types: [NotificationType.COMMENT_ON_PAGE],
+          timeWindow: 3600000, // 1 hour
+          minCount: 2,
+          aggregationType: 'actor_based',
+        },
+      ],
+      [
+        NotificationType.MENTION_IN_COMMENT,
+        {
+          types: [
+            NotificationType.MENTION_IN_COMMENT,
+            NotificationType.MENTION_IN_PAGE,
+          ],
+          timeWindow: 1800000, // 30 minutes
+          minCount: 3,
+          aggregationType: 'count_based',
+        },
+      ],
+      [
+        NotificationType.COMMENT_IN_THREAD,
+        {
+          types: [NotificationType.COMMENT_IN_THREAD],
+          timeWindow: 3600000, // 1 hour
+          minCount: 2,
+          aggregationType: 'actor_based',
+        },
+      ],
+    ]);
+
+  constructor(
+    private readonly aggregationRepo: NotificationAggregationRepo,
+    private readonly notificationRepo: NotificationRepo,
+  ) {}
+
+  async aggregateNotifications(
+    recipientId: string,
+    type: NotificationType,
+    entityId: string,
+    timeWindow: number = 3600000, // 1 hour default
+  ): Promise<NotificationAggregation | null> {
+    const aggregationKey = this.generateAggregationKey(
+      recipientId,
+      type,
+      entityId,
+    );
+
+    // Check if there's an existing aggregation within time window
+    const existing = await this.aggregationRepo.findByKey(aggregationKey);
+
+    if (existing && this.isWithinTimeWindow(existing.updatedAt, timeWindow)) {
+      return existing;
+    }
+
+    // Find recent notifications to aggregate
+    const recentNotifications = await this.notificationRepo.findRecent({
+      recipientId,
+      type,
+      entityId,
+      since: new Date(Date.now() - timeWindow),
+    });
+
+    const rule = this.aggregationRules.get(type);
+    if (!rule || recentNotifications.length < rule.minCount) {
+      return null;
+    }
+
+    // Create new aggregation
+    return await this.createAggregation(
+      aggregationKey,
+      recentNotifications,
+      type,
+    );
+  }
+
+  async updateAggregation(
+    aggregation: NotificationAggregation,
+    notification: Notification,
+  ): Promise<void> {
+    await this.aggregationRepo.addNotificationToAggregation(
+      aggregation.aggregationKey,
+      notification.id,
+      notification.actorId || undefined,
+    );
+
+    this.logger.debug(
+      `Updated aggregation ${aggregation.id} with notification ${notification.id}`,
+    );
+  }
+
+  private async createAggregation(
+    key: string,
+    notifications: Notification[],
+    type: NotificationType,
+  ): Promise<NotificationAggregation> {
+    const actors = [
+      ...new Set(notifications.map((n) => n.actorId).filter(Boolean)),
+    ];
+    const notificationIds = notifications.map((n) => n.id);
+
+    const summaryData = {
+      totalCount: notifications.length,
+      actorCount: actors.length,
+      firstActorId: actors[0],
+      recentActors: actors.slice(0, 3),
+      timeSpan: {
+        start: notifications[notifications.length - 1].createdAt.toISOString(),
+        end: notifications[0].createdAt.toISOString(),
+      },
+    };
+
+    const aggregation = await this.aggregationRepo.insertAggregation({
+      aggregationKey: key,
+      recipientId: notifications[0].recipientId,
+      aggregationType: this.getAggregationType(type),
+      entityType: notifications[0].entityType,
+      entityId: notifications[0].entityId,
+      actorIds: actors,
+      notificationIds: notificationIds,
+      summaryData: summaryData,
+    });
+
+    this.logger.log(
+      `Created aggregation ${aggregation.id} for ${notifications.length} notifications`,
+    );
+
+    return aggregation;
+  }
+
+  private generateAggregationKey(
+    recipientId: string,
+    type: NotificationType,
+    entityId: string,
+  ): string {
+    return `${recipientId}:${type}:${entityId}`;
+  }
+
+  private isWithinTimeWindow(updatedAt: Date, timeWindow: number): boolean {
+    return Date.now() - updatedAt.getTime() < timeWindow;
+  }
+
+  private getAggregationType(type: NotificationType): AggregationType {
+    switch (type) {
+      case NotificationType.COMMENT_ON_PAGE:
+      case NotificationType.COMMENT_RESOLVED:
+        return AggregationType.COMMENTS_ON_PAGE;
+
+      case NotificationType.MENTION_IN_PAGE:
+        return AggregationType.MENTIONS_IN_PAGE;
+
+      case NotificationType.MENTION_IN_COMMENT:
+        return AggregationType.MENTIONS_IN_COMMENTS;
+
+      case NotificationType.COMMENT_IN_THREAD:
+        return AggregationType.THREAD_ACTIVITY;
+
+      default:
+        return AggregationType.COMMENTS_ON_PAGE;
+    }
+  }
+
+  async createAggregatedNotificationMessage(
+    aggregation: NotificationAggregation,
+  ): Promise<AggregatedNotificationMessage> {
+    // TODO: Load actor information from user service
+    // For now, return a simplified version
+    const actors = aggregation.actorIds.slice(0, 3).map((id) => ({
+      id,
+      name: 'User', // TODO: Load actual user name
+      avatarUrl: undefined,
+    }));
+
+    const primaryActor = actors[0];
+    const otherActorsCount = aggregation.actorIds.length - 1;
+
+    let message: string;
+    let title: string;
+
+    switch (aggregation.aggregationType) {
+      case AggregationType.COMMENTS_ON_PAGE:
+        if (otherActorsCount === 0) {
+          title = `${primaryActor.name} commented on a page`;
+          message = 'View the comment';
+        } else if (otherActorsCount === 1) {
+          title = `${primaryActor.name} and 1 other commented on a page`;
+          message = 'View 2 comments';
+        } else {
+          title = `${primaryActor.name} and ${otherActorsCount} others commented on a page`;
+          message = `View ${aggregation.notificationIds.length} comments`;
+        }
+        break;
+
+      case AggregationType.MENTIONS_IN_PAGE:
+      case AggregationType.MENTIONS_IN_COMMENTS: {
+        const totalMentions = aggregation.notificationIds.length;
+        if (totalMentions === 1) {
+          title = `${primaryActor.name} mentioned you`;
+          message = 'View mention';
+        } else {
+          title = `You were mentioned ${totalMentions} times`;
+          message = `By ${primaryActor.name} and ${otherActorsCount} others`;
+        }
+        break;
+      }
+
+      default:
+        title = `${aggregation.notificationIds.length} new notifications`;
+        message = 'View all';
+    }
+
+    return {
+      id: aggregation.id,
+      title,
+      message,
+      actors,
+      totalCount: aggregation.notificationIds.length,
+      entityId: aggregation.entityId,
+      entityType: aggregation.entityType,
+      createdAt: aggregation.createdAt,
+      updatedAt: aggregation.updatedAt,
+    };
+  }
+
+  async cleanupOldAggregations(olderThan: Date): Promise<number> {
+    const deletedCount =
+      await this.aggregationRepo.deleteOldAggregations(olderThan);
+
+    if (deletedCount > 0) {
+      this.logger.log(`Cleaned up ${deletedCount} old aggregations`);
+    }
+
+    return deletedCount;
+  }
+}

apps/server/src/core/notification/services/notification-batching.service.ts

@@ -0,0 +1,215 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { InjectQueue } from '@nestjs/bullmq';
+import { Queue } from 'bullmq';
+import { NotificationRepo } from '../../../database/repos/notification/notification.repo';
+import { NotificationBatchRepo } from '../../../database/repos/notification/notification-batch.repo';
+import { NotificationPreferenceService } from './notification-preference.service';
+import { Notification } from '@docmost/db/types/entity.types';
+import { NotificationType, BatchType } from '../types/notification.types';
+
+interface NotificationGroup {
+  type: NotificationType;
+  entityId: string;
+  entityType: string;
+  notifications: Notification[];
+  actors: Set<string>;
+  summary: string;
+}
+
+@Injectable()
+export class NotificationBatchingService {
+  private readonly logger = new Logger(NotificationBatchingService.name);
+
+  constructor(
+    private readonly notificationRepo: NotificationRepo,
+    private readonly batchRepo: NotificationBatchRepo,
+    private readonly preferenceService: NotificationPreferenceService,
+    @InjectQueue('notification-batch') private readonly batchQueue: Queue,
+  ) {}
+
+  async addToBatch(notification: Notification): Promise<void> {
+    try {
+      const preferences = await this.preferenceService.getUserPreferences(
+        notification.recipientId,
+        notification.workspaceId,
+      );
+
+      const batchKey = this.generateBatchKey(notification);
+      
+      // Find or create batch
+      let batch = await this.batchRepo.findByBatchKey(
+        batchKey,
+        notification.recipientId,
+        true, // notSentOnly
+      );
+
+      if (!batch) {
+        // Create new batch
+        const scheduledFor = new Date();
+        scheduledFor.setMinutes(scheduledFor.getMinutes() + preferences.batchWindowMinutes);
+
+        batch = await this.batchRepo.insertBatch({
+          recipientId: notification.recipientId,
+          workspaceId: notification.workspaceId,
+          batchType: BatchType.SIMILAR_ACTIVITY,
+          batchKey: batchKey,
+          notificationCount: 1,
+          firstNotificationId: notification.id,
+          scheduledFor: scheduledFor,
+        });
+
+        // Schedule batch processing
+        await this.batchQueue.add(
+          'process-batch',
+          { batchId: batch.id },
+          {
+            delay: preferences.batchWindowMinutes * 60 * 1000,
+          },
+        );
+      } else {
+        // Add to existing batch
+        await this.batchRepo.incrementNotificationCount(batch.id);
+      }
+
+      // Update notification with batch ID
+      await this.notificationRepo.updateNotification(notification.id, {
+        batchId: batch.id,
+        isBatched: true,
+      });
+
+      this.logger.debug(`Notification ${notification.id} added to batch ${batch.id}`);
+    } catch (error) {
+      this.logger.error(
+        `Failed to batch notification ${notification.id}: ${error instanceof Error ? error.message : String(error)}`,
+        error instanceof Error ? error.stack : undefined,
+      );
+      // Fall back to instant delivery on error
+      throw error;
+    }
+  }
+
+  private generateBatchKey(notification: Notification): string {
+    switch (notification.type) {
+      case NotificationType.COMMENT_ON_PAGE:
+      case NotificationType.COMMENT_RESOLVED: {
+        const context = notification.context as any;
+        return `page:${context?.pageId}:comments`;
+      }
+
+      case NotificationType.MENTION_IN_PAGE:
+        return `page:${notification.entityId}:mentions`;
+
+      case NotificationType.COMMENT_IN_THREAD: {
+        const mentionContext = notification.context as any;
+        return `thread:${mentionContext?.threadRootId}`;
+      }
+
+      default:
+        return `${notification.entityType}:${notification.entityId}:${notification.type}`;
+    }
+  }
+
+  async processBatch(batchId: string): Promise<void> {
+    const batch = await this.batchRepo.findById(batchId);
+    if (!batch || batch.sentAt) {
+      this.logger.debug(`Batch ${batchId} not found or already sent`);
+      return;
+    }
+
+    const notifications = await this.notificationRepo.findByBatchId(batchId);
+
+    if (notifications.length === 0) {
+      this.logger.debug(`No notifications found for batch ${batchId}`);
+      return;
+    }
+
+    // Group notifications by type for smart formatting
+    const grouped = this.groupNotificationsByType(notifications);
+
+    // Send batch email
+    await this.sendBatchEmail(batch.recipientId, batch.workspaceId, grouped);
+
+    // Mark batch as sent
+    await this.batchRepo.markAsSent(batchId);
+
+    // Update email sent timestamp for all notifications
+    const notificationIds = notifications.map(n => n.id);
+    await Promise.all(
+      notificationIds.map(id =>
+        this.notificationRepo.updateNotification(id, { emailSentAt: new Date() })
+      ),
+    );
+
+    this.logger.log(`Batch ${batchId} processed with ${notifications.length} notifications`);
+  }
+
+  private groupNotificationsByType(notifications: Notification[]): NotificationGroup[] {
+    const groups = new Map<string, NotificationGroup>();
+
+    for (const notification of notifications) {
+      const key = `${notification.type}:${notification.entityId}`;
+
+      if (!groups.has(key)) {
+        groups.set(key, {
+          type: notification.type as NotificationType,
+          entityId: notification.entityId,
+          entityType: notification.entityType,
+          notifications: [],
+          actors: new Set(),
+          summary: '',
+        });
+      }
+
+      const group = groups.get(key)!;
+      group.notifications.push(notification);
+      if (notification.actorId) {
+        group.actors.add(notification.actorId);
+      }
+    }
+
+    // Generate summaries for each group
+    for (const group of groups.values()) {
+      group.summary = this.generateSummary(group.type, group.notifications);
+    }
+
+    return Array.from(groups.values());
+  }
+
+  private generateSummary(type: NotificationType, notifications: Notification[]): string {
+    const count = notifications.length;
+    const actors = new Set(notifications.map(n => n.actorId).filter(Boolean));
+
+    switch (type) {
+      case NotificationType.COMMENT_ON_PAGE:
+        if (count === 1) return 'commented on a page you follow';
+        return `and ${actors.size - 1} others commented on a page you follow`;
+
+      case NotificationType.MENTION_IN_COMMENT:
+        if (count === 1) return 'mentioned you in a comment';
+        return `mentioned you ${count} times in comments`;
+
+      case NotificationType.COMMENT_RESOLVED:
+        if (count === 1) return 'resolved a comment';
+        return `resolved ${count} comments`;
+
+      default:
+        return `${count} new activities`;
+    }
+  }
+
+  private async sendBatchEmail(
+    recipientId: string,
+    workspaceId: string,
+    groups: NotificationGroup[],
+  ): Promise<void> {
+    // TODO: Implement email sending with batch template
+    // This will be implemented when we create email templates
+    this.logger.log(
+      `Sending batch email to ${recipientId} with ${groups.length} notification groups`,
+    );
+  }
+
+  async getPendingBatches(): Promise<any[]> {
+    return await this.batchRepo.getPendingBatches();
+  }
+}

apps/server/src/core/notification/services/notification-deduplication.service.ts

@@ -0,0 +1,151 @@
+import { Injectable } from '@nestjs/common';
+import { NotificationType } from '../types/notification.types';
+import { CreateNotificationDto } from '../dto/create-notification.dto';
+import { createHash } from 'crypto';
+
+@Injectable()
+export class NotificationDeduplicationService {
+  /**
+   * Generate a unique deduplication key based on notification type and context
+   */
+  generateDeduplicationKey(params: CreateNotificationDto): string | null {
+    switch (params.type) {
+      case NotificationType.MENTION_IN_PAGE:
+        // Only one notification per mention in a page (until page is updated again)
+        return this.hash([
+          'mention',
+          'page',
+          params.entityId,
+          params.actorId,
+          params.recipientId,
+        ]);
+
+      case NotificationType.MENTION_IN_COMMENT:
+        // One notification per comment mention
+        return this.hash([
+          'mention',
+          'comment',
+          params.entityId,
+          params.actorId,
+          params.recipientId,
+        ]);
+
+      case NotificationType.COMMENT_ON_PAGE:
+        // Allow multiple notifications for different comments on the same page
+        return null; // No deduplication, rely on batching instead
+
+      case NotificationType.REPLY_TO_COMMENT:
+        // One notification per reply
+        return this.hash([
+          'reply',
+          params.entityId,
+          params.actorId,
+          params.recipientId,
+        ]);
+
+      case NotificationType.COMMENT_RESOLVED:
+        // One notification per comment resolution
+        return this.hash([
+          'resolved',
+          params.context.commentId,
+          params.actorId,
+          params.recipientId,
+        ]);
+
+      case NotificationType.EXPORT_COMPLETED:
+      case NotificationType.EXPORT_FAILED:
+        // One notification per export job
+        return this.hash([
+          'export',
+          params.context.jobId || params.entityId,
+          params.recipientId,
+        ]);
+
+      case NotificationType.PAGE_SHARED:
+        // One notification per page share action
+        return this.hash([
+          'share',
+          params.entityId,
+          params.actorId,
+          params.recipientId,
+          Date.now().toString(), // Include timestamp to allow re-sharing
+        ]);
+
+      default:
+        // For other types, generate a key based on common fields
+        return this.hash([
+          params.type,
+          params.entityId,
+          params.actorId,
+          params.recipientId,
+        ]);
+    }
+  }
+
+  /**
+   * Check if a notification should be deduplicated based on recent activity
+   */
+  shouldDeduplicate(type: NotificationType): boolean {
+    const deduplicatedTypes = [
+      NotificationType.MENTION_IN_PAGE,
+      NotificationType.MENTION_IN_COMMENT,
+      NotificationType.REPLY_TO_COMMENT,
+      NotificationType.COMMENT_RESOLVED,
+      NotificationType.EXPORT_COMPLETED,
+      NotificationType.EXPORT_FAILED,
+    ];
+
+    return deduplicatedTypes.includes(type);
+  }
+
+  /**
+   * Get the time window for deduplication (in milliseconds)
+   */
+  getDeduplicationWindow(type: NotificationType): number {
+    switch (type) {
+      case NotificationType.MENTION_IN_PAGE:
+        return 24 * 60 * 60 * 1000; // 24 hours
+
+      case NotificationType.MENTION_IN_COMMENT:
+        return 60 * 60 * 1000; // 1 hour
+
+      case NotificationType.EXPORT_COMPLETED:
+      case NotificationType.EXPORT_FAILED:
+        return 5 * 60 * 1000; // 5 minutes
+
+      default:
+        return 30 * 60 * 1000; // 30 minutes default
+    }
+  }
+
+  /**
+   * Create a hash from array of values
+   */
+  private hash(values: (string | null | undefined)[]): string {
+    const filtered = values.filter((v) => v !== null && v !== undefined);
+    const input = filtered.join(':');
+    return createHash('sha256').update(input).digest('hex').substring(0, 32);
+  }
+
+  /**
+   * Generate a key for custom deduplication scenarios
+   */
+  generateCustomKey(
+    type: string,
+    entityId: string,
+    recipientId: string,
+    additionalData?: Record<string, any>,
+  ): string {
+    const baseValues = [type, entityId, recipientId];
+
+    if (additionalData) {
+      // Sort keys for consistent hashing
+      const sortedKeys = Object.keys(additionalData).sort();
+      for (const key of sortedKeys) {
+        baseValues.push(`${key}:${additionalData[key]}`);
+      }
+    }
+
+    return this.hash(baseValues);
+  }
+}

apps/server/src/core/notification/services/notification-delivery.service.ts

@@ -0,0 +1,194 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { OnEvent } from '@nestjs/event-emitter';
+import { InjectQueue } from '@nestjs/bullmq';
+import { Queue } from 'bullmq';
+import { QueueName } from '../../../integrations/queue/constants';
+import { WsGateway } from '../../../ws/ws.gateway';
+import { NotificationBatchingService } from './notification-batching.service';
+import { NotificationPreferenceService } from './notification-preference.service';
+import { NotificationRepo } from '@docmost/db/repos/notification/notification.repo';
+import { Notification } from '@docmost/db/types/entity.types';
+import {
+  NotificationCreatedEvent,
+  NotificationReadEvent,
+  NotificationAllReadEvent,
+  NOTIFICATION_EVENTS,
+} from '../events/notification.events';
+import { NotificationType, NotificationPriority } from '../types/notification.types';
+
+@Injectable()
+export class NotificationDeliveryService {
+  private readonly logger = new Logger(NotificationDeliveryService.name);
+
+  constructor(
+    @InjectQueue(QueueName.EMAIL_QUEUE) private readonly mailQueue: Queue,
+    private readonly wsGateway: WsGateway,
+    private readonly batchingService: NotificationBatchingService,
+    private readonly preferenceService: NotificationPreferenceService,
+    private readonly notificationRepo: NotificationRepo,
+  ) {}
+
+  @OnEvent(NOTIFICATION_EVENTS.CREATED)
+  async handleNotificationCreated(event: NotificationCreatedEvent) {
+    const { notification, workspaceId } = event;
+
+    try {
+      const decision = await this.preferenceService.makeNotificationDecision(
+        notification.recipientId,
+        workspaceId,
+        notification.type as NotificationType,
+        notification.priority as NotificationPriority,
+      );
+
+      // In-app delivery (always immediate)
+      if (decision.channels.includes('in_app')) {
+        await this.deliverInApp(notification, workspaceId);
+      }
+
+      // Email delivery (may be batched)
+      if (decision.channels.includes('email')) {
+        if (decision.batchingEnabled) {
+          await this.batchingService.addToBatch(notification);
+        } else {
+          await this.deliverEmailInstant(notification);
+        }
+      }
+    } catch (error) {
+      this.logger.error(
+        `Failed to deliver notification ${notification.id}: ${error instanceof Error ? error.message : String(error)}`,
+        error instanceof Error ? error.stack : undefined,
+      );
+    }
+  }
+
+  private async deliverInApp(notification: Notification, workspaceId: string) {
+    try {
+      // Send notification via WebSocket to user's workspace room
+      const notificationData = {
+        id: notification.id,
+        type: notification.type,
+        status: notification.status,
+        priority: notification.priority,
+        actorId: notification.actorId,
+        entityType: notification.entityType,
+        entityId: notification.entityId,
+        context: notification.context,
+        createdAt: notification.createdAt,
+      };
+
+      // Emit to user-specific room
+      this.wsGateway.emitToUser(
+        notification.recipientId,
+        'notification:new',
+        notificationData,
+      );
+
+      // Update unread count
+      const unreadCount = await this.notificationRepo.getUnreadCount(
+        notification.recipientId,
+      );
+      this.wsGateway.emitToUser(
+        notification.recipientId,
+        'notification:unreadCount',
+        { count: unreadCount },
+      );
+
+      // Update delivery status
+      await this.notificationRepo.updateNotification(notification.id, {
+        inAppDeliveredAt: new Date(),
+      });
+
+      this.logger.debug(`In-app notification delivered: ${notification.id}`);
+    } catch (error) {
+      this.logger.error(
+        `Failed to deliver in-app notification ${notification.id}: ${error instanceof Error ? error.message : String(error)}`,
+        error instanceof Error ? error.stack : undefined,
+      );
+    }
+  }
+
+  private async deliverEmailInstant(notification: Notification) {
+    try {
+      await this.mailQueue.add(
+        'send-notification-email',
+        {
+          notificationId: notification.id,
+          type: notification.type,
+        },
+        {
+          attempts: 3,
+          backoff: {
+            type: 'exponential',
+            delay: 2000,
+          },
+        },
+      );
+
+      this.logger.debug(`Email notification queued: ${notification.id}`);
+    } catch (error) {
+      this.logger.error(
+        `Failed to queue email notification ${notification.id}: ${error instanceof Error ? error.message : String(error)}`,
+        error instanceof Error ? error.stack : undefined,
+      );
+    }
+  }
+
+  @OnEvent(NOTIFICATION_EVENTS.READ)
+  async handleNotificationRead(event: NotificationReadEvent) {
+    const { notificationId, userId } = event;
+
+    // Send real-time update to user
+    this.wsGateway.emitToUser(userId, 'notification:read', {
+      notificationId,
+    });
+
+    // Update unread count
+    const unreadCount = await this.notificationRepo.getUnreadCount(userId);
+    this.wsGateway.emitToUser(userId, 'notification:unreadCount', {
+      count: unreadCount,
+    });
+  }
+
+  @OnEvent(NOTIFICATION_EVENTS.ALL_READ)
+  async handleAllNotificationsRead(event: NotificationAllReadEvent) {
+    const { userId, notificationIds } = event;
+
+    // Send real-time update to user
+    this.wsGateway.emitToUser(userId, 'notification:allRead', {
+      notificationIds,
+    });
+
+    // Update unread count (should be 0)
+    this.wsGateway.emitToUser(userId, 'notification:unreadCount', { count: 0 });
+  }
+
+  /**
+   * Process email delivery for a notification
+   * Called by the mail queue processor
+   */
+  async processEmailNotification(notificationId: string) {
+    const notification = await this.notificationRepo.findById(notificationId);
+    if (!notification) {
+      throw new Error(`Notification not found: ${notificationId}`);
+    }
+
+    // Check if already sent
+    if (notification.emailSentAt) {
+      this.logger.debug(
+        `Notification already sent via email: ${notificationId}`,
+      );
+      return;
+    }
+
+    // TODO: Load user and workspace data
+    // TODO: Render appropriate email template based on notification type
+    // TODO: Send email using mail service
+
+    // For now, just mark as sent
+    await this.notificationRepo.updateNotification(notificationId, {
+      emailSentAt: new Date(),
+    });
+
+    this.logger.log(`Email notification sent: ${notificationId}`);
+  }
+}

apps/server/src/core/notification/services/notification-preference.service.ts

@@ -0,0 +1,303 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { NotificationPreferenceRepo } from '@docmost/db/repos/notification/notification-preference.repo';
+import { UpdateNotificationPreferencesDto } from '../dto/update-preference.dto';
+import { NotificationPreference } from '@docmost/db/types/entity.types';
+import {
+  NotificationType,
+  NotificationPriority,
+} from '../types/notification.types';
+import { 
+  addDays, 
+  setHours, 
+  setMinutes, 
+  setSeconds,
+  getDay,
+  differenceInMilliseconds,
+  startOfDay,
+  addHours
+} from 'date-fns';
+
+interface NotificationDecision {
+  shouldNotify: boolean;
+  channels: ('email' | 'in_app')[];
+  delay?: number;
+  batchingEnabled: boolean;
+}
+
+@Injectable()
+export class NotificationPreferenceService {
+  private readonly logger = new Logger(NotificationPreferenceService.name);
+
+  constructor(private readonly preferenceRepo: NotificationPreferenceRepo) {}
+
+  async getUserPreferences(
+    userId: string,
+    workspaceId: string,
+  ): Promise<NotificationPreference> {
+    return await this.preferenceRepo.findOrCreate(userId, workspaceId);
+  }
+
+  async updateUserPreferences(
+    userId: string,
+    workspaceId: string,
+    updates: UpdateNotificationPreferencesDto,
+  ): Promise<NotificationPreference> {
+    const existing = await this.getUserPreferences(userId, workspaceId);
+
+    // Merge notification settings if provided
+    let mergedSettings = existing.notificationSettings;
+    if (updates.notificationSettings) {
+      mergedSettings = {
+        ...((existing.notificationSettings as Record<string, any>) || {}),
+        ...(updates.notificationSettings || {}),
+      };
+    }
+
+    // Validate batch window
+    if (updates.batchWindowMinutes !== undefined) {
+      updates.batchWindowMinutes = Math.max(
+        5,
+        Math.min(60, updates.batchWindowMinutes),
+      );
+    }
+
+    const updated = await this.preferenceRepo.updatePreference(
+      userId,
+      workspaceId,
+      {
+        ...updates,
+        notificationSettings: mergedSettings,
+      },
+    );
+
+    this.logger.log(`User ${userId} updated notification preferences`, {
+      userId,
+      workspaceId,
+      changes: updates,
+    });
+
+    return updated;
+  }
+
+  async shouldNotify(
+    recipientId: string,
+    type: NotificationType,
+    workspaceId: string,
+  ): Promise<boolean> {
+    const preferences = await this.getUserPreferences(recipientId, workspaceId);
+    const decision = await this.makeNotificationDecision(
+      recipientId,
+      workspaceId,
+      type,
+      NotificationPriority.NORMAL,
+    );
+
+    return decision.shouldNotify;
+  }
+
+  async makeNotificationDecision(
+    userId: string,
+    workspaceId: string,
+    type: NotificationType,
+    priority: NotificationPriority = NotificationPriority.NORMAL,
+  ): Promise<NotificationDecision> {
+    const preferences = await this.getUserPreferences(userId, workspaceId);
+
+    // Global check
+    if (!preferences.emailEnabled && !preferences.inAppEnabled) {
+      return {
+        shouldNotify: false,
+        channels: [],
+        batchingEnabled: false,
+      };
+    }
+
+    // Type-specific settings
+    const typeSettings = this.getTypeSettings(preferences, type);
+
+    const channels: ('email' | 'in_app')[] = [];
+    if (preferences.emailEnabled && typeSettings.email) channels.push('email');
+    if (preferences.inAppEnabled && typeSettings.in_app)
+      channels.push('in_app');
+
+    if (channels.length === 0) {
+      return {
+        shouldNotify: false,
+        channels: [],
+        batchingEnabled: false,
+      };
+    }
+
+    // Check quiet hours
+    const quietHoursDelay = this.calculateQuietHoursDelay(
+      preferences,
+      priority,
+    );
+
+    // Check weekend preferences
+    if (
+      !preferences.weekendNotifications &&
+      this.isWeekend(preferences.timezone)
+    ) {
+      if (priority !== NotificationPriority.HIGH) {
+        const mondayDelay = this.getDelayUntilMonday(preferences.timezone);
+        return {
+          shouldNotify: true,
+          channels,
+          delay: mondayDelay,
+          batchingEnabled: true,
+        };
+      }
+    }
+
+    return {
+      shouldNotify: true,
+      channels,
+      delay: quietHoursDelay,
+      batchingEnabled:
+        typeSettings.batch && preferences.emailFrequency === 'smart',
+    };
+  }
+
+  private getTypeSettings(
+    preferences: NotificationPreference,
+    type: NotificationType,
+  ): any {
+    const settings = preferences.notificationSettings as any;
+    return settings[type] || { email: true, in_app: true, batch: false };
+  }
+
+  private calculateQuietHoursDelay(
+    preferences: NotificationPreference,
+    priority: NotificationPriority,
+  ): number | undefined {
+    if (
+      !preferences.quietHoursEnabled ||
+      priority === NotificationPriority.HIGH
+    ) {
+      return undefined;
+    }
+
+    // TODO: Implement proper timezone conversion
+    const now = new Date();
+    const quietStart = this.parseTime(
+      preferences.quietHoursStart,
+      preferences.timezone,
+    );
+    const quietEnd = this.parseTime(
+      preferences.quietHoursEnd,
+      preferences.timezone,
+    );
+
+    if (this.isInQuietHours(now, quietStart, quietEnd)) {
+      return this.getDelayUntilEndOfQuietHours(now, quietEnd);
+    }
+
+    return undefined;
+  }
+
+  private parseTime(timeStr: string, timezone: string): Date {
+    const [hours, minutes, seconds] = timeStr.split(':').map(Number);
+    // TODO: Implement proper timezone conversion
+    const now = new Date();
+    return setSeconds(setMinutes(setHours(now, hours), minutes), seconds || 0);
+  }
+
+  private isInQuietHours(
+    now: Date,
+    start: Date,
+    end: Date,
+  ): boolean {
+    const nowMinutes = now.getHours() * 60 + now.getMinutes();
+    const startMinutes = start.getHours() * 60 + start.getMinutes();
+    const endMinutes = end.getHours() * 60 + end.getMinutes();
+
+    if (startMinutes <= endMinutes) {
+      // Quiet hours don't cross midnight
+      return nowMinutes >= startMinutes && nowMinutes < endMinutes;
+    } else {
+      // Quiet hours cross midnight
+      return nowMinutes >= startMinutes || nowMinutes < endMinutes;
+    }
+  }
+
+  private getDelayUntilEndOfQuietHours(now: Date, end: Date): number {
+    let endTime = end;
+
+    // If end time is before current time, it means quiet hours end tomorrow
+    if (
+      end.getHours() < now.getHours() ||
+      (end.getHours() === now.getHours() && end.getMinutes() <= now.getMinutes())
+    ) {
+      endTime = addDays(endTime, 1);
+    }
+
+    return differenceInMilliseconds(endTime, now);
+  }
+
+  private isWeekend(timezone: string): boolean {
+    // TODO: Implement proper timezone conversion
+    const now = new Date();
+    const dayOfWeek = getDay(now);
+    return dayOfWeek === 0 || dayOfWeek === 6; // 0 = Sunday, 6 = Saturday
+  }
+
+  private getDelayUntilMonday(timezone: string): number {
+    // TODO: Implement proper timezone conversion
+    const now = new Date();
+    const currentDay = getDay(now);
+    const daysUntilMonday = currentDay === 0 ? 1 : (8 - currentDay) % 7 || 7;
+    const nextMonday = addDays(now, daysUntilMonday);
+    const mondayMorning = addHours(startOfDay(nextMonday), 9); // 9 AM Monday
+    return differenceInMilliseconds(mondayMorning, now);
+  }
+
+  async getNotificationStats(
+    userId: string,
+    workspaceId: string,
+  ): Promise<{
+    preferences: NotificationPreference;
+    stats: {
+      emailEnabled: boolean;
+      inAppEnabled: boolean;
+      quietHoursActive: boolean;
+      batchingEnabled: boolean;
+      typesDisabled: string[];
+    };
+  }> {
+    const preferences = await this.getUserPreferences(userId, workspaceId);
+    // TODO: Implement proper timezone conversion
+    const now = new Date();
+    const quietStart = this.parseTime(
+      preferences.quietHoursStart,
+      preferences.timezone,
+    );
+    const quietEnd = this.parseTime(
+      preferences.quietHoursEnd,
+      preferences.timezone,
+    );
+
+    const typesDisabled: string[] = [];
+    const settings = preferences.notificationSettings as any;
+
+    for (const [type, config] of Object.entries(settings)) {
+      const typeSettings = config as any;
+      if (!typeSettings.email && !typeSettings.in_app) {
+        typesDisabled.push(type);
+      }
+    }
+
+    return {
+      preferences,
+      stats: {
+        emailEnabled: preferences.emailEnabled,
+        inAppEnabled: preferences.inAppEnabled,
+        quietHoursActive:
+          preferences.quietHoursEnabled &&
+          this.isInQuietHours(now, quietStart, quietEnd),
+        batchingEnabled: preferences.emailFrequency !== 'instant',
+        typesDisabled,
+      },
+    };
+  }
+}

apps/server/src/core/notification/services/notification.service.ts

@@ -0,0 +1,275 @@
+import { Injectable, Logger } from '@nestjs/common';
+import { EventEmitter2 } from '@nestjs/event-emitter';
+import { NotificationRepo } from '@docmost/db/repos/notification/notification.repo';
+import { NotificationDeduplicationService } from './notification-deduplication.service';
+import { NotificationPreferenceService } from './notification-preference.service';
+import { CreateNotificationDto } from '../dto/create-notification.dto';
+import { Notification } from '@docmost/db/types/entity.types';
+import {
+  NotificationStatus,
+  NotificationPriority,
+  NotificationType,
+} from '../types/notification.types';
+import {
+  NotificationCreatedEvent,
+  NotificationReadEvent,
+  NotificationAllReadEvent,
+  NOTIFICATION_EVENTS,
+} from '../events/notification.events';
+
+@Injectable()
+export class NotificationService {
+  private readonly logger = new Logger(NotificationService.name);
+
+  constructor(
+    private readonly notificationRepo: NotificationRepo,
+    private readonly eventEmitter: EventEmitter2,
+    private readonly deduplicationService: NotificationDeduplicationService,
+    private readonly preferenceService: NotificationPreferenceService,
+  ) {}
+
+  async createNotification(
+    dto: CreateNotificationDto,
+  ): Promise<Notification | null> {
+    try {
+      // Set default priority if not provided
+      const priority = dto.priority || NotificationPriority.NORMAL;
+
+      // Check user preferences first
+      const decision = await this.preferenceService.makeNotificationDecision(
+        dto.recipientId,
+        dto.workspaceId,
+        dto.type,
+        priority,
+      );
+
+      if (!decision.shouldNotify) {
+        this.logger.debug(
+          `Notification blocked by user preferences: ${dto.type} for ${dto.recipientId}`,
+        );
+        return null;
+      }
+
+      // Generate deduplication key
+      let deduplicationKey = dto.deduplicationKey;
+      if (
+        !deduplicationKey &&
+        this.deduplicationService.shouldDeduplicate(dto.type)
+      ) {
+        deduplicationKey =
+          this.deduplicationService.generateDeduplicationKey(dto);
+      }
+
+      // Check if duplicate
+      if (
+        deduplicationKey &&
+        (await this.notificationRepo.existsByDeduplicationKey(deduplicationKey))
+      ) {
+        this.logger.debug(
+          `Duplicate notification prevented: ${deduplicationKey}`,
+        );
+        return null;
+      }
+
+      // Generate group key if not provided
+      const groupKey = dto.groupKey || this.generateGroupKey(dto);
+
+      // Calculate expiration
+      const expiresAt = this.calculateExpiration(dto.type);
+
+      // Create notification
+      const notification = await this.notificationRepo.insertNotification({
+        workspaceId: dto.workspaceId,
+        recipientId: dto.recipientId,
+        actorId: dto.actorId || null,
+        type: dto.type,
+        status: NotificationStatus.UNREAD,
+        priority,
+        entityType: dto.entityType,
+        entityId: dto.entityId,
+        context: dto.context,
+        groupKey: groupKey,
+        groupCount: 1,
+        deduplicationKey: deduplicationKey,
+        batchId: null,
+        isBatched: false,
+        emailSentAt: null,
+        inAppDeliveredAt: null,
+        readAt: null,
+        expiresAt: expiresAt,
+      });
+
+      // Emit event for delivery processing
+      this.eventEmitter.emit(
+        NOTIFICATION_EVENTS.CREATED,
+        new NotificationCreatedEvent(notification, dto.workspaceId),
+      );
+
+      this.logger.debug(
+        `Notification created: ${notification.id} for user ${dto.recipientId}`,
+      );
+
+      return notification;
+    } catch (error) {
+      this.logger.error(
+        `Failed to create notification: ${error instanceof Error ? error.message : String(error)}`,
+        error instanceof Error ? error.stack : undefined,
+      );
+      throw error;
+    }
+  }
+
+  async getNotifications(
+    userId: string,
+    workspaceId: string,
+    options: {
+      status?: NotificationStatus;
+      limit?: number;
+      offset?: number;
+    } = {},
+  ): Promise<Notification[]> {
+    return await this.notificationRepo.findByRecipient(userId, options);
+  }
+
+  async getGroupedNotifications(
+    userId: string,
+    workspaceId: string,
+    options: {
+      status?: NotificationStatus;
+      limit?: number;
+      offset?: number;
+    } = {},
+  ): Promise<{
+    notifications: Notification[];
+    groups: Map<string, Notification[]>;
+  }> {
+    const notifications = await this.getNotifications(
+      userId,
+      workspaceId,
+      options,
+    );
+
+    // Group notifications by group_key
+    const groups = new Map<string, Notification[]>();
+
+    for (const notification of notifications) {
+      if (notification.groupKey) {
+        const group = groups.get(notification.groupKey) || [];
+        group.push(notification);
+        groups.set(notification.groupKey, group);
+      }
+    }
+
+    return { notifications, groups };
+  }
+
+  async markAsRead(notificationId: string, userId: string): Promise<void> {
+    const notification = await this.notificationRepo.findById(notificationId);
+
+    if (!notification || notification.recipientId !== userId) {
+      throw new Error('Notification not found or unauthorized');
+    }
+
+    if (notification.status === NotificationStatus.READ) {
+      return; // Already read
+    }
+
+    await this.notificationRepo.markAsRead(notificationId);
+
+    // Emit event for real-time update
+    this.eventEmitter.emit(
+      NOTIFICATION_EVENTS.READ,
+      new NotificationReadEvent(notificationId, userId),
+    );
+
+    this.logger.debug(`Notification marked as read: ${notificationId}`);
+  }
+
+  async markAllAsRead(userId: string): Promise<void> {
+    const unreadNotifications = await this.notificationRepo.findByRecipient(
+      userId,
+      {
+        status: NotificationStatus.UNREAD,
+      },
+    );
+
+    const ids = unreadNotifications.map((n) => n.id);
+
+    if (ids.length > 0) {
+      await this.notificationRepo.markManyAsRead(ids);
+
+      // Emit event for real-time update
+      this.eventEmitter.emit(
+        NOTIFICATION_EVENTS.ALL_READ,
+        new NotificationAllReadEvent(userId, ids),
+      );
+
+      this.logger.debug(
+        `Marked ${ids.length} notifications as read for user ${userId}`,
+      );
+    }
+  }
+
+  async getUnreadCount(userId: string): Promise<number> {
+    return await this.notificationRepo.getUnreadCount(userId);
+  }
+
+  async deleteExpiredNotifications(): Promise<number> {
+    const deletedCount = await this.notificationRepo.deleteExpired();
+
+    if (deletedCount > 0) {
+      this.logger.log(`Deleted ${deletedCount} expired notifications`);
+    }
+
+    return deletedCount;
+  }
+
+  private generateGroupKey(dto: CreateNotificationDto): string {
+    // Generate a group key based on notification type and entity
+    return `${dto.type}:${dto.entityType}:${dto.entityId}`;
+  }
+
+  private calculateExpiration(type: string): Date | null {
+    // Set expiration based on notification type
+    const expirationDays = {
+      [NotificationType.EXPORT_COMPLETED]: 7, // Expire after 7 days
+      [NotificationType.EXPORT_FAILED]: 3, // Expire after 3 days
+      [NotificationType.MENTION_IN_PAGE]: 30, // Expire after 30 days
+      [NotificationType.MENTION_IN_COMMENT]: 30,
+      [NotificationType.COMMENT_ON_PAGE]: 60, // Expire after 60 days
+      [NotificationType.REPLY_TO_COMMENT]: 60,
+      [NotificationType.COMMENT_IN_THREAD]: 60,
+      [NotificationType.COMMENT_RESOLVED]: 90, // Expire after 90 days
+      [NotificationType.PAGE_SHARED]: 90,
+    };
+
+    const days = expirationDays[type as NotificationType];
+    if (!days) {
+      return null; // No expiration
+    }
+
+    const expirationDate = new Date();
+    expirationDate.setDate(expirationDate.getDate() + days);
+    return expirationDate;
+  }
+
+  async createTestNotification(
+    userId: string,
+    workspaceId: string,
+    type: NotificationType,
+  ): Promise<Notification | null> {
+    return await this.createNotification({
+      workspaceId,
+      recipientId: userId,
+      actorId: userId,
+      type,
+      entityType: 'test',
+      entityId: 'test-notification',
+      context: {
+        message: 'This is a test notification',
+        timestamp: new Date(),
+      },
+      priority: NotificationPriority.NORMAL,
+    });
+  }
+}

apps/server/src/core/notification/templates/batch-notification.template.tsx

@@ -0,0 +1,153 @@
+import * as React from 'react';
+import { Button, Section, Text, Link, Hr, Heading } from '@react-email/components';
+import { MailBody } from '@docmost/transactional/partials/partials';
+import { content, paragraph, button, h1 } from '@docmost/transactional/css/styles';
+
+interface NotificationGroup {
+  type: string;
+  title: string;
+  summary: string;
+  count: number;
+  actors: string[];
+  url: string;
+  preview: string[];
+}
+
+interface BatchNotificationEmailProps {
+  recipientName: string;
+  groups: NotificationGroup[];
+  totalCount: number;
+  workspaceName: string;
+  settingsUrl: string;
+  viewAllUrl: string;
+}
+
+export const BatchNotificationEmail = ({
+  recipientName,
+  groups,
+  totalCount,
+  workspaceName,
+  settingsUrl,
+  viewAllUrl,
+}: BatchNotificationEmailProps) => {
+  return (
+    <MailBody>
+      <Section style={content}>
+        <Text style={h1}>Hi {recipientName},</Text>
+        
+        <Text style={paragraph}>
+          You have {totalCount} new notifications in {workspaceName}:
+        </Text>
+
+        {groups.map((group, index) => (
+          <Section key={index} style={notificationGroup}>
+            <Heading as="h3" style={groupTitle}>
+              {group.title}
+            </Heading>
+            
+            <Text style={actorList}>
+              {formatActors(group.actors)} {group.summary}
+            </Text>
+            
+            {group.preview.slice(0, 3).map((item, i) => (
+              <Text key={i} style={notificationItem}>
+                • {item}
+              </Text>
+            ))}
+            
+            {group.count > 3 && (
+              <Text style={moreText}>
+                And {group.count - 3} more...
+              </Text>
+            )}
+            
+            <Button href={group.url} style={viewButton}>
+              View All
+            </Button>
+          </Section>
+        ))}
+
+        <Hr style={divider} />
+
+        <Button href={viewAllUrl} style={viewAllButton}>
+          View All Notifications
+        </Button>
+        
+        <Text style={footerText}>
+          You received this because you have smart notifications enabled.{' '}
+          <Link href={settingsUrl} style={{ color: '#176ae5' }}>
+            Manage your preferences
+          </Link>
+        </Text>
+      </Section>
+    </MailBody>
+  );
+};
+
+function formatActors(actors: string[]): string {
+  if (actors.length === 0) return '';
+  if (actors.length === 1) return actors[0];
+  if (actors.length === 2) return `${actors[0]} and ${actors[1]}`;
+  return `${actors[0]}, ${actors[1]} and ${actors.length - 2} others`;
+}
+
+const notificationGroup: React.CSSProperties = {
+  backgroundColor: '#f9f9f9',
+  borderRadius: '4px',
+  padding: '16px',
+  marginBottom: '16px',
+};
+
+const groupTitle: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '16px',
+  fontWeight: 'bold',
+  marginBottom: '8px',
+};
+
+const actorList: React.CSSProperties = {
+  ...paragraph,
+  marginBottom: '12px',
+};
+
+const notificationItem: React.CSSProperties = {
+  ...paragraph,
+  marginLeft: '8px',
+  marginBottom: '4px',
+  color: '#666',
+};
+
+const moreText: React.CSSProperties = {
+  ...paragraph,
+  fontStyle: 'italic',
+  color: '#999',
+  marginLeft: '8px',
+  marginBottom: '12px',
+};
+
+const viewButton: React.CSSProperties = {
+  ...button,
+  width: 'auto',
+  padding: '8px 16px',
+  fontSize: '14px',
+  marginTop: '8px',
+};
+
+const viewAllButton: React.CSSProperties = {
+  ...button,
+  width: 'auto',
+  padding: '12px 24px',
+  margin: '16px auto',
+};
+
+const divider: React.CSSProperties = {
+  borderColor: '#e0e0e0',
+  margin: '24px 0',
+};
+
+const footerText: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '12px',
+  color: '#666',
+  marginTop: '24px',
+};

apps/server/src/core/notification/templates/comment-on-page.template.tsx

@@ -0,0 +1,72 @@
+import * as React from 'react';
+import { Button, Section, Text, Link } from '@react-email/components';
+import { MailBody } from '../../../integrations/transactional/partials/partials';
+import { content, paragraph, button, h1 } from '../../../integrations/transactional/css/styles';
+
+interface CommentOnPageEmailProps {
+  recipientName: string;
+  actorName: string;
+  pageTitle: string;
+  commentExcerpt: string;
+  pageUrl: string;
+  workspaceName: string;
+  settingsUrl: string;
+}
+
+export const CommentOnPageEmail = ({
+  recipientName,
+  actorName,
+  pageTitle,
+  commentExcerpt,
+  pageUrl,
+  workspaceName,
+  settingsUrl,
+}: CommentOnPageEmailProps) => {
+  return (
+    <MailBody>
+      <Section style={content}>
+        <Text style={h1}>Hi {recipientName},</Text>
+        
+        <Text style={paragraph}>
+          {actorName} commented on "{pageTitle}":
+        </Text>
+
+        <Section style={commentSection}>
+          <Text style={commentText}>
+            {commentExcerpt}
+          </Text>
+        </Section>
+
+        <Button href={pageUrl} style={button}>
+          View Comment
+        </Button>
+
+        <Text style={footerText}>
+          This notification was sent from {workspaceName}.{' '}
+          <Link href={settingsUrl} style={{ color: '#176ae5' }}>
+            Manage your notification preferences
+          </Link>
+        </Text>
+      </Section>
+    </MailBody>
+  );
+};
+
+const commentSection: React.CSSProperties = {
+  backgroundColor: '#f5f5f5',
+  borderRadius: '4px',
+  padding: '16px',
+  margin: '16px 0',
+};
+
+const commentText: React.CSSProperties = {
+  ...paragraph,
+  margin: 0,
+};
+
+const footerText: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '12px',
+  color: '#666',
+  marginTop: '24px',
+};

apps/server/src/core/notification/templates/export-completed.template.tsx

@@ -0,0 +1,117 @@
+import * as React from 'react';
+import { Button, Section, Text, Link, Row, Column } from '@react-email/components';
+import { MailBody } from '../../../integrations/transactional/partials/partials';
+import { content, paragraph, button, h1 } from '../../../integrations/transactional/css/styles';
+
+interface ExportCompletedEmailProps {
+  recipientName: string;
+  exportType: string;
+  entityName: string;
+  fileSize: string;
+  downloadUrl: string;
+  expiresAt: string;
+  workspaceName: string;
+  settingsUrl: string;
+}
+
+export const ExportCompletedEmail = ({
+  recipientName,
+  exportType,
+  entityName,
+  fileSize,
+  downloadUrl,
+  expiresAt,
+  workspaceName,
+  settingsUrl,
+}: ExportCompletedEmailProps) => {
+  return (
+    <MailBody>
+      <Section style={content}>
+        <Text style={h1}>Export Complete!</Text>
+        
+        <Text style={paragraph}>
+          Hi {recipientName},
+        </Text>
+        
+        <Text style={paragraph}>
+          Your {exportType.toUpperCase()} export of "{entityName}" has been completed successfully.
+        </Text>
+
+        <Section style={exportDetails}>
+          <Row>
+            <Column style={detailLabel}>File Size:</Column>
+            <Column style={detailValue}>{fileSize}</Column>
+          </Row>
+          <Row>
+            <Column style={detailLabel}>Format:</Column>
+            <Column style={detailValue}>{exportType.toUpperCase()}</Column>
+          </Row>
+          <Row>
+            <Column style={detailLabel}>Expires:</Column>
+            <Column style={detailValue}>{expiresAt}</Column>
+          </Row>
+        </Section>
+
+        <Button href={downloadUrl} style={downloadButton}>
+          Download Export
+        </Button>
+        
+        <Text style={warningText}>
+          ⚠️ This download link will expire on {expiresAt}.
+          Please download your file before then.
+        </Text>
+
+        <Text style={footerText}>
+          This notification was sent from {workspaceName}.{' '}
+          <Link href={settingsUrl} style={{ color: '#176ae5' }}>
+            Manage your notification preferences
+          </Link>
+        </Text>
+      </Section>
+    </MailBody>
+  );
+};
+
+const exportDetails: React.CSSProperties = {
+  backgroundColor: '#f5f5f5',
+  borderRadius: '4px',
+  padding: '16px',
+  margin: '16px 0',
+};
+
+const detailLabel: React.CSSProperties = {
+  ...paragraph,
+  fontWeight: 'bold',
+  width: '120px',
+  paddingBottom: '8px',
+};
+
+const detailValue: React.CSSProperties = {
+  ...paragraph,
+  paddingBottom: '8px',
+};
+
+const downloadButton: React.CSSProperties = {
+  ...button,
+  backgroundColor: '#28a745',
+  width: 'auto',
+  padding: '12px 24px',
+  margin: '0 auto',
+};
+
+const warningText: React.CSSProperties = {
+  ...paragraph,
+  backgroundColor: '#fff3cd',
+  border: '1px solid #ffeeba',
+  borderRadius: '4px',
+  color: '#856404',
+  padding: '12px',
+  marginTop: '16px',
+};
+
+const footerText: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '12px',
+  color: '#666',
+  marginTop: '24px',
+};

apps/server/src/core/notification/templates/mention-in-comment.template.tsx

@@ -0,0 +1,93 @@
+import * as React from 'react';
+import { Button, Section, Text, Link } from '@react-email/components';
+import { MailBody } from '../../../integrations/transactional/partials/partials';
+import { content, paragraph, button, h1 } from '../../../integrations/transactional/css/styles';
+
+interface MentionInCommentEmailProps {
+  recipientName: string;
+  actorName: string;
+  pageTitle: string;
+  commentExcerpt: string;
+  mentionContext: string;
+  commentUrl: string;
+  workspaceName: string;
+  settingsUrl: string;
+}
+
+export const MentionInCommentEmail = ({
+  recipientName,
+  actorName,
+  pageTitle,
+  commentExcerpt,
+  mentionContext,
+  commentUrl,
+  workspaceName,
+  settingsUrl,
+}: MentionInCommentEmailProps) => {
+  return (
+    <MailBody>
+      <Section style={content}>
+        <Text style={h1}>Hi {recipientName},</Text>
+        
+        <Text style={paragraph}>
+          {actorName} mentioned you in a comment on "{pageTitle}":
+        </Text>
+
+        <Section style={commentSection}>
+          <Text style={commentAuthor}>{actorName} commented:</Text>
+          <Text style={commentText}>
+            {commentExcerpt}
+          </Text>
+          {mentionContext && (
+            <Text style={mentionHighlight}>
+              Context: ...{mentionContext}...
+            </Text>
+          )}
+        </Section>
+
+        <Button href={commentUrl} style={button}>
+          View Comment
+        </Button>
+
+        <Text style={footerText}>
+          This notification was sent from {workspaceName}.{' '}
+          <Link href={settingsUrl} style={{ color: '#176ae5' }}>
+            Manage your notification preferences
+          </Link>
+        </Text>
+      </Section>
+    </MailBody>
+  );
+};
+
+const commentSection: React.CSSProperties = {
+  backgroundColor: '#f5f5f5',
+  borderRadius: '4px',
+  padding: '16px',
+  margin: '16px 0',
+};
+
+const commentAuthor: React.CSSProperties = {
+  ...paragraph,
+  fontWeight: 'bold',
+  marginBottom: '8px',
+};
+
+const commentText: React.CSSProperties = {
+  ...paragraph,
+  margin: '0 0 8px 0',
+};
+
+const mentionHighlight: React.CSSProperties = {
+  ...paragraph,
+  fontStyle: 'italic',
+  color: '#666',
+  margin: 0,
+};
+
+const footerText: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '12px',
+  color: '#666',
+  marginTop: '24px',
+};

apps/server/src/core/notification/templates/mention-in-page.template.tsx

@@ -0,0 +1,73 @@
+import * as React from 'react';
+import { Button, Section, Text, Link } from '@react-email/components';
+import { MailBody } from '../../../integrations/transactional/partials/partials';
+import { content, paragraph, button, h1 } from '../../../integrations/transactional/css/styles';
+
+interface MentionInPageEmailProps {
+  recipientName: string;
+  actorName: string;
+  pageTitle: string;
+  mentionContext: string;
+  pageUrl: string;
+  workspaceName: string;
+  settingsUrl: string;
+}
+
+export const MentionInPageEmail = ({
+  recipientName,
+  actorName,
+  pageTitle,
+  mentionContext,
+  pageUrl,
+  workspaceName,
+  settingsUrl,
+}: MentionInPageEmailProps) => {
+  return (
+    <MailBody>
+      <Section style={content}>
+        <Text style={h1}>Hi {recipientName},</Text>
+        
+        <Text style={paragraph}>
+          {actorName} mentioned you in the page "{pageTitle}":
+        </Text>
+
+        <Section style={mentionSection}>
+          <Text style={mentionText}>
+            ...{mentionContext}...
+          </Text>
+        </Section>
+
+        <Button href={pageUrl} style={button}>
+          View Page
+        </Button>
+
+        <Text style={footerText}>
+          This notification was sent from {workspaceName}.{' '}
+          <Link href={settingsUrl} style={{ color: '#176ae5' }}>
+            Manage your notification preferences
+          </Link>
+        </Text>
+      </Section>
+    </MailBody>
+  );
+};
+
+const mentionSection: React.CSSProperties = {
+  backgroundColor: '#f5f5f5',
+  borderRadius: '4px',
+  padding: '16px',
+  margin: '16px 0',
+};
+
+const mentionText: React.CSSProperties = {
+  ...paragraph,
+  fontStyle: 'italic',
+  margin: 0,
+};
+
+const footerText: React.CSSProperties = {
+  ...paragraph,
+  fontSize: '12px',
+  color: '#666',
+  marginTop: '24px',
+};

apps/server/src/core/notification/types/notification.types.ts

@@ -0,0 +1,220 @@
+export enum NotificationType {
+  // Mentions
+  MENTION_IN_PAGE = 'mention_in_page',
+  MENTION_IN_COMMENT = 'mention_in_comment',
+  
+  // Comments
+  COMMENT_ON_PAGE = 'comment_on_page',
+  REPLY_TO_COMMENT = 'reply_to_comment',
+  COMMENT_IN_THREAD = 'comment_in_thread',
+  COMMENT_RESOLVED = 'comment_resolved',
+  
+  // Exports
+  EXPORT_COMPLETED = 'export_completed',
+  EXPORT_FAILED = 'export_failed',
+  
+  // Pages
+  PAGE_SHARED = 'page_shared',
+  PAGE_UPDATED = 'page_updated',
+  
+  // Tasks (Future)
+  TASK_ASSIGNED = 'task_assigned',
+  TASK_DUE = 'task_due',
+  TASK_COMPLETED = 'task_completed',
+  
+  // System
+  SYSTEM_UPDATE = 'system_update',
+  SYSTEM_ANNOUNCEMENT = 'system_announcement',
+}
+
+export enum NotificationStatus {
+  UNREAD = 'unread',
+  READ = 'read',
+  ARCHIVED = 'archived',
+}
+
+export enum NotificationPriority {
+  HIGH = 'high',
+  NORMAL = 'normal',
+  LOW = 'low',
+}
+
+export enum EmailFrequency {
+  INSTANT = 'instant',
+  SMART = 'smart',
+  DIGEST_DAILY = 'digest_daily',
+  DIGEST_WEEKLY = 'digest_weekly',
+}
+
+export interface NotificationTypeSettings {
+  email: boolean;
+  in_app: boolean;
+  batch: boolean;
+}
+
+export enum BatchType {
+  SIMILAR_ACTIVITY = 'similar_activity',
+  DIGEST = 'digest',
+  GROUPED_MENTIONS = 'grouped_mentions',
+}
+
+export enum AggregationType {
+  COMMENTS_ON_PAGE = 'comments_on_page',
+  MENTIONS_IN_PAGE = 'mentions_in_page',
+  MENTIONS_IN_COMMENTS = 'mentions_in_comments',
+  THREAD_ACTIVITY = 'thread_activity',
+}
+
+export interface AggregationSummaryData {
+  total_count: number;
+  actor_count: number;
+  first_actor_id: string;
+  recent_actors: string[];
+  time_span: {
+    start: Date;
+    end: Date;
+  };
+  [key: string]: any; // Allow additional type-specific data
+}
+
+export interface AggregatedNotificationMessage {
+  id: string;
+  title: string;
+  message: string;
+  actors: Array<{
+    id: string;
+    name: string;
+    avatarUrl?: string;
+  }>;
+  totalCount: number;
+  entityId: string;
+  entityType: string;
+  createdAt: Date;
+  updatedAt: Date;
+}
+
+// Context interfaces for different notification types
+export interface MentionInPageContext {
+  pageId: string;
+  pageTitle: string;
+  mentionContext: string;
+  mentionBy: string;
+}
+
+export interface MentionInCommentContext {
+  pageId: string;
+  pageTitle: string;
+  commentId: string;
+  commentText: string;
+  mentionBy: string;
+}
+
+export interface CommentOnPageContext {
+  pageId: string;
+  pageTitle: string;
+  commentId: string;
+  commentText: string;
+  commentBy: string;
+}
+
+export interface ReplyToCommentContext {
+  pageId: string;
+  pageTitle: string;
+  commentId: string;
+  parentCommentId: string;
+  commentText: string;
+  replyBy: string;
+}
+
+export interface CommentInThreadContext {
+  pageId: string;
+  pageTitle: string;
+  threadId: string;
+  commentId: string;
+  commentText: string;
+  commentBy: string;
+}
+
+export interface CommentResolvedContext {
+  pageId: string;
+  pageTitle: string;
+  threadId: string;
+  resolvedBy: string;
+}
+
+export interface ExportCompletedContext {
+  exportId: string;
+  exportType: string;
+  downloadUrl: string;
+  expiresAt: string;
+}
+
+export interface ExportFailedContext {
+  exportId: string;
+  exportType: string;
+  errorMessage: string;
+}
+
+export interface PageSharedContext {
+  pageId: string;
+  pageTitle: string;
+  sharedBy: string;
+  sharedWith: string[];
+  permissions: string[];
+}
+
+export interface PageUpdatedContext {
+  pageId: string;
+  pageTitle: string;
+  updatedBy: string;
+  changeType: 'content' | 'title' | 'permissions';
+}
+
+export interface TaskAssignedContext {
+  taskId: string;
+  taskTitle: string;
+  assignedBy: string;
+  dueDate?: string;
+}
+
+export interface TaskDueContext {
+  taskId: string;
+  taskTitle: string;
+  dueDate: string;
+  daysOverdue?: number;
+}
+
+export interface TaskCompletedContext {
+  taskId: string;
+  taskTitle: string;
+  completedBy: string;
+}
+
+export interface SystemUpdateContext {
+  updateType: string;
+  version?: string;
+  description: string;
+}
+
+export interface SystemAnnouncementContext {
+  message: string;
+  link?: string;
+}
+
+export type NotificationContext = 
+  | MentionInPageContext
+  | MentionInCommentContext
+  | CommentOnPageContext
+  | ReplyToCommentContext
+  | CommentInThreadContext
+  | CommentResolvedContext
+  | ExportCompletedContext
+  | ExportFailedContext
+  | PageSharedContext
+  | PageUpdatedContext
+  | TaskAssignedContext
+  | TaskDueContext
+  | TaskCompletedContext
+  | SystemUpdateContext
+  | SystemAnnouncementContext
+  | Record<string, unknown>;

apps/server/src/core/search/search.service.ts

@@ -140,7 +140,7 @@ export class SearchService {
     if (suggestion.includeUsers) {
       users = await this.db
         .selectFrom('users')
-        .select(['id', 'name', 'email', 'avatarUrl'])
+        .select(['id', 'name', 'avatarUrl'])
         .where((eb) => eb(sql`LOWER(users.name)`, 'like', `%${query}%`))
         .where('workspaceId', '=', workspaceId)
         .where('deletedAt', 'is', null)

apps/server/src/database/database.module.ts

@@ -25,6 +25,10 @@ import { MigrationService } from '@docmost/db/services/migration.service';
 import { UserTokenRepo } from './repos/user-token/user-token.repo';
 import { BacklinkRepo } from '@docmost/db/repos/backlink/backlink.repo';
 import { ShareRepo } from '@docmost/db/repos/share/share.repo';
+import { NotificationRepo } from './repos/notification/notification.repo';
+import { NotificationPreferenceRepo } from './repos/notification/notification-preference.repo';
+import { NotificationBatchRepo } from './repos/notification/notification-batch.repo';
+import { NotificationAggregationRepo } from './repos/notification/notification-aggregation.repo';
 
 // https://github.com/brianc/node-postgres/issues/811
 types.setTypeParser(types.builtins.INT8, (val) => Number(val));
@@ -75,7 +79,11 @@ types.setTypeParser(types.builtins.INT8, (val) => Number(val));
     AttachmentRepo,
     UserTokenRepo,
     BacklinkRepo,
-    ShareRepo
+    ShareRepo,
+    NotificationRepo,
+    NotificationPreferenceRepo,
+    NotificationBatchRepo,
+    NotificationAggregationRepo,
   ],
   exports: [
     WorkspaceRepo,
@@ -90,7 +98,11 @@ types.setTypeParser(types.builtins.INT8, (val) => Number(val));
     AttachmentRepo,
     UserTokenRepo,
     BacklinkRepo,
-    ShareRepo
+    ShareRepo,
+    NotificationRepo,
+    NotificationPreferenceRepo,
+    NotificationBatchRepo,
+    NotificationAggregationRepo,
   ],
 })
 export class DatabaseModule

apps/server/src/database/migrations/20250710T092527-create-notification-tables.ts

@@ -0,0 +1,233 @@
+import { Kysely, sql } from 'kysely';
+
+export async function up(db: Kysely<any>): Promise<void> {
+  // Create notifications table
+  await db.schema
+    .createTable('notifications')
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.notNull().references('workspaces.id').onDelete('cascade'),
+    )
+    .addColumn('recipient_id', 'uuid', (col) =>
+      col.notNull().references('users.id').onDelete('cascade'),
+    )
+    .addColumn('actor_id', 'uuid', (col) =>
+      col.references('users.id').onDelete('set null'),
+    )
+    .addColumn('type', 'varchar(50)', (col) => col.notNull())
+    .addColumn('status', 'varchar(20)', (col) =>
+      col.notNull().defaultTo('unread'),
+    )
+    .addColumn('priority', 'varchar(20)', (col) =>
+      col.notNull().defaultTo('normal'),
+    )
+    .addColumn('entity_type', 'varchar(50)', (col) => col.notNull())
+    .addColumn('entity_id', 'uuid', (col) => col.notNull())
+    .addColumn('context', 'jsonb', (col) => col.notNull().defaultTo('{}'))
+    .addColumn('group_key', 'varchar(255)')
+    .addColumn('group_count', 'integer', (col) => col.defaultTo(1))
+    .addColumn('deduplication_key', 'varchar(255)')
+    .addColumn('batch_id', 'uuid')
+    .addColumn('is_batched', 'boolean', (col) => col.defaultTo(false))
+    .addColumn('email_sent_at', 'timestamp')
+    .addColumn('in_app_delivered_at', 'timestamp')
+    .addColumn('read_at', 'timestamp')
+    .addColumn('created_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .addColumn('updated_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .addColumn('expires_at', 'timestamp')
+    .execute();
+
+  // Create indexes for notifications
+  await db.schema
+    .createIndex('idx_notifications_recipient_status')
+    .on('notifications')
+    .columns(['recipient_id', 'status'])
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notifications_group_key')
+    .on('notifications')
+    .columns(['group_key', 'created_at'])
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notifications_batch_pending')
+    .on('notifications')
+    .columns(['batch_id', 'is_batched'])
+    .where('is_batched', '=', false)
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notifications_expires')
+    .on('notifications')
+    .column('expires_at')
+    .where('expires_at', 'is not', null)
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notifications_deduplication')
+    .unique()
+    .on('notifications')
+    .column('deduplication_key')
+    .where('deduplication_key', 'is not', null)
+    .execute();
+
+  // Create notification_preferences table
+  await db.schema
+    .createTable('notification_preferences')
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('user_id', 'uuid', (col) =>
+      col.notNull().references('users.id').onDelete('cascade'),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.notNull().references('workspaces.id').onDelete('cascade'),
+    )
+    .addColumn('email_enabled', 'boolean', (col) =>
+      col.notNull().defaultTo(true),
+    )
+    .addColumn('in_app_enabled', 'boolean', (col) =>
+      col.notNull().defaultTo(true),
+    )
+    .addColumn('notification_settings', 'jsonb', (col) =>
+      col.notNull().defaultTo(sql`'{
+        "mention_in_page": {"email": true, "in_app": true, "batch": false},
+        "mention_in_comment": {"email": true, "in_app": true, "batch": false},
+        "comment_on_page": {"email": true, "in_app": true, "batch": true},
+        "reply_to_comment": {"email": true, "in_app": true, "batch": false},
+        "comment_in_thread": {"email": true, "in_app": true, "batch": true},
+        "comment_resolved": {"email": true, "in_app": true, "batch": true},
+        "export_completed": {"email": true, "in_app": true, "batch": false},
+        "page_shared": {"email": true, "in_app": true, "batch": true},
+        "task_assigned": {"email": true, "in_app": true, "batch": false}
+      }'::jsonb`),
+    )
+    .addColumn('batch_window_minutes', 'integer', (col) => col.defaultTo(15))
+    .addColumn('max_batch_size', 'integer', (col) => col.defaultTo(20))
+    .addColumn('batch_types', sql`text[]`, (col) =>
+      col.defaultTo(
+        sql`ARRAY['comment_on_page', 'comment_in_thread', 'comment_resolved']`,
+      ),
+    )
+    .addColumn('email_frequency', 'varchar(20)', (col) =>
+      col.notNull().defaultTo('smart'),
+    )
+    .addColumn('digest_time', 'time', (col) => col.defaultTo('09:00:00'))
+    .addColumn('quiet_hours_enabled', 'boolean', (col) => col.defaultTo(false))
+    .addColumn('quiet_hours_start', 'time', (col) => col.defaultTo('18:00:00'))
+    .addColumn('quiet_hours_end', 'time', (col) => col.defaultTo('09:00:00'))
+    .addColumn('timezone', 'varchar(50)', (col) => col.defaultTo('UTC'))
+    .addColumn('weekend_notifications', 'boolean', (col) => col.defaultTo(true))
+    .addColumn('created_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .addColumn('updated_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .execute();
+
+  // Create unique index for user_workspace
+  await db.schema
+    .createIndex('idx_notification_preferences_user_workspace')
+    .unique()
+    .on('notification_preferences')
+    .columns(['user_id', 'workspace_id'])
+    .execute();
+
+  // Create notification_batches table
+  await db.schema
+    .createTable('notification_batches')
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('recipient_id', 'uuid', (col) =>
+      col.notNull().references('users.id').onDelete('cascade'),
+    )
+    .addColumn('workspace_id', 'uuid', (col) =>
+      col.notNull().references('workspaces.id').onDelete('cascade'),
+    )
+    .addColumn('batch_type', 'varchar(50)', (col) => col.notNull())
+    .addColumn('batch_key', 'varchar(255)', (col) => col.notNull())
+    .addColumn('notification_count', 'integer', (col) =>
+      col.notNull().defaultTo(0),
+    )
+    .addColumn('first_notification_id', 'uuid', (col) =>
+      col.references('notifications.id').onDelete('set null'),
+    )
+    .addColumn('scheduled_for', 'timestamp', (col) => col.notNull())
+    .addColumn('sent_at', 'timestamp')
+    .addColumn('created_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .execute();
+
+  // Create indexes for notification_batches
+  await db.schema
+    .createIndex('idx_notification_batches_scheduled_pending')
+    .on('notification_batches')
+    .columns(['scheduled_for', 'sent_at'])
+    .where('sent_at', 'is', null)
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notification_batches_batch_key')
+    .on('notification_batches')
+    .columns(['batch_key', 'recipient_id'])
+    .execute();
+
+  // Create notification_aggregations table
+  await db.schema
+    .createTable('notification_aggregations')
+    .addColumn('id', 'uuid', (col) =>
+      col.primaryKey().defaultTo(sql`gen_uuid_v7()`),
+    )
+    .addColumn('aggregation_key', 'varchar(255)', (col) => col.notNull())
+    .addColumn('recipient_id', 'uuid', (col) =>
+      col.notNull().references('users.id').onDelete('cascade'),
+    )
+    .addColumn('aggregation_type', 'varchar(50)', (col) => col.notNull())
+    .addColumn('entity_type', 'varchar(50)', (col) => col.notNull())
+    .addColumn('entity_id', 'uuid', (col) => col.notNull())
+    .addColumn('actor_ids', sql`uuid[]`, (col) =>
+      col.notNull().defaultTo(sql`'{}'`),
+    )
+    .addColumn('notification_ids', sql`uuid[]`, (col) =>
+      col.notNull().defaultTo(sql`'{}'`),
+    )
+    .addColumn('summary_data', 'jsonb', (col) => col.notNull().defaultTo('{}'))
+    .addColumn('created_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .addColumn('updated_at', 'timestamp', (col) =>
+      col.notNull().defaultTo(sql`CURRENT_TIMESTAMP`),
+    )
+    .execute();
+
+  // Create indexes for notification_aggregations
+  await db.schema
+    .createIndex('idx_notification_aggregations_key')
+    .unique()
+    .on('notification_aggregations')
+    .column('aggregation_key')
+    .execute();
+
+  await db.schema
+    .createIndex('idx_notification_aggregations_recipient_updated')
+    .on('notification_aggregations')
+    .columns(['recipient_id', 'updated_at'])
+    .execute();
+}
+
+export async function down(db: Kysely<any>): Promise<void> {
+  await db.schema.dropTable('notification_aggregations').ifExists().execute();
+  await db.schema.dropTable('notification_batches').ifExists().execute();
+  await db.schema.dropTable('notification_preferences').ifExists().execute();
+  await db.schema.dropTable('notifications').ifExists().execute();
+}

apps/server/src/database/repos/notification/notification-aggregation.repo.ts

@@ -0,0 +1,125 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB } from '@docmost/db/types/kysely.types';
+import { 
+  NotificationAggregation, 
+  InsertableNotificationAggregation, 
+  UpdatableNotificationAggregation 
+} from '@docmost/db/types/entity.types';
+
+@Injectable()
+export class NotificationAggregationRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  async insertAggregation(aggregation: InsertableNotificationAggregation): Promise<NotificationAggregation> {
+    return await this.db
+      .insertInto('notificationAggregations')
+      .values(aggregation)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async findById(id: string): Promise<NotificationAggregation | undefined> {
+    return await this.db
+      .selectFrom('notificationAggregations')
+      .selectAll()
+      .where('id', '=', id)
+      .executeTakeFirst();
+  }
+
+  async findByKey(aggregationKey: string): Promise<NotificationAggregation | undefined> {
+    return await this.db
+      .selectFrom('notificationAggregations')
+      .selectAll()
+      .where('aggregationKey', '=', aggregationKey)
+      .executeTakeFirst();
+  }
+
+  async updateAggregation(
+    aggregationKey: string,
+    update: UpdatableNotificationAggregation
+  ): Promise<NotificationAggregation> {
+    return await this.db
+      .updateTable('notificationAggregations')
+      .set({
+        ...update,
+        updatedAt: new Date(),
+      })
+      .where('aggregationKey', '=', aggregationKey)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async addNotificationToAggregation(
+    aggregationKey: string,
+    notificationId: string,
+    actorId?: string
+  ): Promise<void> {
+    const aggregation = await this.findByKey(aggregationKey);
+    if (!aggregation) {
+      throw new Error(`Aggregation not found: ${aggregationKey}`);
+    }
+
+    const updates: UpdatableNotificationAggregation = {
+      notificationIds: [...aggregation.notificationIds, notificationId],
+      updatedAt: new Date(),
+    };
+
+    if (actorId && !aggregation.actorIds.includes(actorId)) {
+      updates.actorIds = [...aggregation.actorIds, actorId];
+    }
+
+    // Update summary data
+    updates.summaryData = {
+      ...(aggregation.summaryData as Record<string, any> || {}),
+      totalCount: aggregation.notificationIds.length + 1,
+      actorCount: updates.actorIds?.length || aggregation.actorIds.length,
+      timeSpan: {
+        ...((aggregation.summaryData as any).timeSpan || {}),
+        end: new Date(),
+      },
+    };
+
+    await this.updateAggregation(aggregationKey, updates);
+  }
+
+  async findRecentByRecipient(
+    recipientId: string,
+    limit = 10
+  ): Promise<NotificationAggregation[]> {
+    return await this.db
+      .selectFrom('notificationAggregations')
+      .selectAll()
+      .where('recipientId', '=', recipientId)
+      .orderBy('updatedAt', 'desc')
+      .limit(limit)
+      .execute();
+  }
+
+  async deleteOldAggregations(olderThan: Date): Promise<number> {
+    const result = await this.db
+      .deleteFrom('notificationAggregations')
+      .where('updatedAt', '<', olderThan)
+      .execute();
+
+    return Number(result[0].numDeletedRows);
+  }
+
+  async getAggregationsByEntity(
+    entityType: string,
+    entityId: string,
+    recipientId?: string
+  ): Promise<NotificationAggregation[]> {
+    let query = this.db
+      .selectFrom('notificationAggregations')
+      .selectAll()
+      .where('entityType', '=', entityType)
+      .where('entityId', '=', entityId);
+
+    if (recipientId) {
+      query = query.where('recipientId', '=', recipientId);
+    }
+
+    return await query.orderBy('updatedAt', 'desc').execute();
+  }
+}

apps/server/src/database/repos/notification/notification-batch.repo.ts

@@ -0,0 +1,110 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB } from '@docmost/db/types/kysely.types';
+import { 
+  NotificationBatch, 
+  InsertableNotificationBatch, 
+  UpdatableNotificationBatch 
+} from '@docmost/db/types/entity.types';
+
+@Injectable()
+export class NotificationBatchRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  async insertBatch(batch: InsertableNotificationBatch): Promise<NotificationBatch> {
+    return await this.db
+      .insertInto('notificationBatches')
+      .values(batch)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async findById(id: string): Promise<NotificationBatch | undefined> {
+    return await this.db
+      .selectFrom('notificationBatches')
+      .selectAll()
+      .where('id', '=', id)
+      .executeTakeFirst();
+  }
+
+  async findByBatchKey(
+    batchKey: string,
+    recipientId: string,
+    notSentOnly = true
+  ): Promise<NotificationBatch | undefined> {
+    let query = this.db
+      .selectFrom('notificationBatches')
+      .selectAll()
+      .where('batchKey', '=', batchKey)
+      .where('recipientId', '=', recipientId);
+
+    if (notSentOnly) {
+      query = query.where('sentAt', 'is', null);
+    }
+
+    return await query.executeTakeFirst();
+  }
+
+  async getPendingBatches(limit = 100): Promise<NotificationBatch[]> {
+    return await this.db
+      .selectFrom('notificationBatches')
+      .selectAll()
+      .where('sentAt', 'is', null)
+      .where('scheduledFor', '<=', new Date())
+      .orderBy('scheduledFor', 'asc')
+      .limit(limit)
+      .execute();
+  }
+
+  async updateBatch(id: string, update: UpdatableNotificationBatch): Promise<NotificationBatch> {
+    return await this.db
+      .updateTable('notificationBatches')
+      .set(update)
+      .where('id', '=', id)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async markAsSent(id: string): Promise<void> {
+    await this.db
+      .updateTable('notificationBatches')
+      .set({
+        sentAt: new Date(),
+      })
+      .where('id', '=', id)
+      .execute();
+  }
+
+  async incrementNotificationCount(id: string): Promise<void> {
+    await this.db
+      .updateTable('notificationBatches')
+      .set((eb) => ({
+        notificationCount: eb('notificationCount', '+', 1),
+      }))
+      .where('id', '=', id)
+      .execute();
+  }
+
+  async deleteOldBatches(olderThan: Date): Promise<number> {
+    const result = await this.db
+      .deleteFrom('notificationBatches')
+      .where('sentAt', '<', olderThan)
+      .execute();
+
+    return Number(result[0].numDeletedRows);
+  }
+
+  async getScheduledBatchesForUser(
+    recipientId: string,
+    workspaceId: string
+  ): Promise<NotificationBatch[]> {
+    return await this.db
+      .selectFrom('notificationBatches')
+      .selectAll()
+      .where('recipientId', '=', recipientId)
+      .where('workspaceId', '=', workspaceId)
+      .where('sentAt', 'is', null)
+      .orderBy('scheduledFor', 'asc')
+      .execute();
+  }
+}

apps/server/src/database/repos/notification/notification-preference.repo.ts

@@ -0,0 +1,134 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB } from '@docmost/db/types/kysely.types';
+import { sql } from 'kysely';
+import { 
+  NotificationPreference, 
+  InsertableNotificationPreference, 
+  UpdatableNotificationPreference 
+} from '@docmost/db/types/entity.types';
+
+export const DEFAULT_NOTIFICATION_SETTINGS = {
+  mention_in_page: { email: true, in_app: true, batch: false },
+  mention_in_comment: { email: true, in_app: true, batch: false },
+  comment_on_page: { email: true, in_app: true, batch: true },
+  reply_to_comment: { email: true, in_app: true, batch: false },
+  comment_in_thread: { email: true, in_app: true, batch: true },
+  comment_resolved: { email: true, in_app: true, batch: true },
+  export_completed: { email: true, in_app: true, batch: false },
+  export_failed: { email: true, in_app: true, batch: false },
+  page_shared: { email: true, in_app: true, batch: true },
+  page_updated: { email: false, in_app: true, batch: true },
+  task_assigned: { email: true, in_app: true, batch: false },
+  task_due_soon: { email: true, in_app: true, batch: false },
+};
+
+@Injectable()
+export class NotificationPreferenceRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  async insertPreference(preference: InsertableNotificationPreference): Promise<NotificationPreference> {
+    return await this.db
+      .insertInto('notificationPreferences')
+      .values(preference)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async findByUserAndWorkspace(
+    userId: string,
+    workspaceId: string
+  ): Promise<NotificationPreference | undefined> {
+    return await this.db
+      .selectFrom('notificationPreferences')
+      .selectAll()
+      .where('userId', '=', userId)
+      .where('workspaceId', '=', workspaceId)
+      .executeTakeFirst();
+  }
+
+  async findOrCreate(
+    userId: string,
+    workspaceId: string
+  ): Promise<NotificationPreference> {
+    const existing = await this.findByUserAndWorkspace(userId, workspaceId);
+    if (existing) {
+      return existing;
+    }
+
+    return await this.insertPreference({
+      userId: userId,
+      workspaceId: workspaceId,
+      emailEnabled: true,
+      inAppEnabled: true,
+      notificationSettings: DEFAULT_NOTIFICATION_SETTINGS,
+      batchWindowMinutes: 15,
+      maxBatchSize: 20,
+      batchTypes: ['comment_on_page', 'comment_in_thread', 'comment_resolved'],
+      emailFrequency: 'smart',
+      digestTime: '09:00:00',
+      quietHoursEnabled: false,
+      quietHoursStart: '18:00:00',
+      quietHoursEnd: '09:00:00',
+      timezone: 'UTC',
+      weekendNotifications: true,
+    });
+  }
+
+  async updatePreference(
+    userId: string,
+    workspaceId: string,
+    update: UpdatableNotificationPreference
+  ): Promise<NotificationPreference> {
+    return await this.db
+      .updateTable('notificationPreferences')
+      .set({
+        ...update,
+        updatedAt: new Date(),
+      })
+      .where('userId', '=', userId)
+      .where('workspaceId', '=', workspaceId)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async findUsersWithBatchingEnabled(
+    workspaceId: string,
+    notificationType: string
+  ): Promise<NotificationPreference[]> {
+    return await this.db
+      .selectFrom('notificationPreferences')
+      .selectAll()
+      .where('workspaceId', '=', workspaceId)
+      .where('emailEnabled', '=', true)
+      .where('emailFrequency', '!=', 'instant')
+      .where(
+        sql<boolean>`notification_settings::jsonb->'${sql.raw(notificationType)}'->>'batch' = 'true'`
+      )
+      .execute();
+  }
+
+  async findUsersForDigest(
+    workspaceId: string,
+    currentTime: string,
+    timezone: string
+  ): Promise<NotificationPreference[]> {
+    return await this.db
+      .selectFrom('notificationPreferences')
+      .selectAll()
+      .where('workspaceId', '=', workspaceId)
+      .where('emailFrequency', '=', 'daily')
+      .where('digestTime', '=', currentTime)
+      .where('timezone', '=', timezone)
+      .where('emailEnabled', '=', true)
+      .execute();
+  }
+
+  async deletePreference(userId: string, workspaceId: string): Promise<void> {
+    await this.db
+      .deleteFrom('notificationPreferences')
+      .where('userId', '=', userId)
+      .where('workspaceId', '=', workspaceId)
+      .execute();
+  }
+}

apps/server/src/database/repos/notification/notification.repo.ts

@@ -0,0 +1,175 @@
+import { Injectable } from '@nestjs/common';
+import { InjectKysely } from 'nestjs-kysely';
+import { KyselyDB } from '@docmost/db/types/kysely.types';
+import { Notification, InsertableNotification, UpdatableNotification } from '@docmost/db/types/entity.types';
+import { PaginationOptions } from '@docmost/db/pagination/pagination-options';
+
+@Injectable()
+export class NotificationRepo {
+  constructor(@InjectKysely() private readonly db: KyselyDB) {}
+
+  async insertNotification(notification: InsertableNotification): Promise<Notification> {
+    return await this.db
+      .insertInto('notifications')
+      .values(notification)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async findById(id: string): Promise<Notification | undefined> {
+    return await this.db
+      .selectFrom('notifications')
+      .selectAll()
+      .where('id', '=', id)
+      .executeTakeFirst();
+  }
+
+  async findByRecipient(
+    recipientId: string,
+    options: {
+      status?: string;
+      limit?: number;
+      offset?: number;
+    } = {}
+  ): Promise<Notification[]> {
+    let query = this.db
+      .selectFrom('notifications')
+      .selectAll()
+      .where('recipientId', '=', recipientId)
+      .orderBy('createdAt', 'desc');
+
+    if (options.status) {
+      query = query.where('status', '=', options.status);
+    }
+
+    if (options.limit) {
+      query = query.limit(options.limit);
+    }
+
+    if (options.offset) {
+      query = query.offset(options.offset);
+    }
+
+    return await query.execute();
+  }
+
+  async findByBatchId(batchId: string): Promise<Notification[]> {
+    return await this.db
+      .selectFrom('notifications')
+      .selectAll()
+      .where('batchId', '=', batchId)
+      .orderBy('createdAt', 'desc')
+      .execute();
+  }
+
+  async findRecent(params: {
+    recipientId: string;
+    type: string;
+    entityId: string;
+    since: Date;
+  }): Promise<Notification[]> {
+    return await this.db
+      .selectFrom('notifications')
+      .selectAll()
+      .where('recipientId', '=', params.recipientId)
+      .where('type', '=', params.type)
+      .where('entityId', '=', params.entityId)
+      .where('createdAt', '>', params.since)
+      .orderBy('createdAt', 'desc')
+      .execute();
+  }
+
+  async existsByDeduplicationKey(key: string): Promise<boolean> {
+    const result = await this.db
+      .selectFrom('notifications')
+      .select(['id'])
+      .where('deduplicationKey', '=', key)
+      .executeTakeFirst();
+
+    return !!result;
+  }
+
+  async updateNotification(id: string, update: UpdatableNotification): Promise<Notification> {
+    return await this.db
+      .updateTable('notifications')
+      .set(update)
+      .where('id', '=', id)
+      .returningAll()
+      .executeTakeFirstOrThrow();
+  }
+
+  async markAsRead(id: string): Promise<void> {
+    await this.db
+      .updateTable('notifications')
+      .set({
+        status: 'read',
+        readAt: new Date(),
+        updatedAt: new Date(),
+      })
+      .where('id', '=', id)
+      .execute();
+  }
+
+  async markManyAsRead(ids: string[]): Promise<void> {
+    if (ids.length === 0) return;
+
+    await this.db
+      .updateTable('notifications')
+      .set({
+        status: 'read',
+        readAt: new Date(),
+        updatedAt: new Date(),
+      })
+      .where('id', 'in', ids)
+      .execute();
+  }
+
+  async getUnreadCount(recipientId: string): Promise<number> {
+    const result = await this.db
+      .selectFrom('notifications')
+      .select((eb) => eb.fn.countAll<number>().as('count'))
+      .where('recipientId', '=', recipientId)
+      .where('status', '=', 'unread')
+      .executeTakeFirst();
+
+    return result?.count || 0;
+  }
+
+  async deleteExpired(): Promise<number> {
+    const result = await this.db
+      .deleteFrom('notifications')
+      .where('expiresAt', '<', new Date())
+      .execute();
+
+    return Number(result[0].numDeletedRows);
+  }
+
+  async getNotificationsByGroupKey(
+    groupKey: string,
+    recipientId: string,
+    since: Date
+  ): Promise<Notification[]> {
+    return await this.db
+      .selectFrom('notifications')
+      .selectAll()
+      .where('groupKey', '=', groupKey)
+      .where('recipientId', '=', recipientId)
+      .where('createdAt', '>', since)
+      .orderBy('createdAt', 'desc')
+      .execute();
+  }
+
+  async updateBatchId(notificationIds: string[], batchId: string): Promise<void> {
+    if (notificationIds.length === 0) return;
+
+    await this.db
+      .updateTable('notifications')
+      .set({
+        batchId: batchId,
+        isBatched: true,
+        updatedAt: new Date(),
+      })
+      .where('id', 'in', notificationIds)
+      .execute();
+  }
+}

apps/server/src/database/types/db.d.ts

@@ -62,6 +62,7 @@ export interface AuthProviders {
   deletedAt: Timestamp | null;
   id: Generated<string>;
   isEnabled: Generated<boolean>;
+  isGroupSyncEnabled: Generated<boolean>;
   name: string;
   oidcClientId: string | null;
   oidcClientSecret: string | null;
@@ -122,6 +123,7 @@ export interface Comments {
   pageId: string;
   parentCommentId: string | null;
   resolvedAt: Timestamp | null;
+  resolvedById: string | null;
   selection: string | null;
   type: string | null;
   workspaceId: string;
@@ -165,6 +167,78 @@ export interface GroupUsers {
   userId: string;
 }
 
+export interface NotificationAggregations {
+  actorIds: Generated<string[]>;
+  aggregationKey: string;
+  aggregationType: string;
+  createdAt: Generated<Timestamp>;
+  entityId: string;
+  entityType: string;
+  id: Generated<string>;
+  notificationIds: Generated<string[]>;
+  recipientId: string;
+  summaryData: Generated<Json>;
+  updatedAt: Generated<Timestamp>;
+}
+
+export interface NotificationBatches {
+  batchKey: string;
+  batchType: string;
+  createdAt: Generated<Timestamp>;
+  firstNotificationId: string | null;
+  id: Generated<string>;
+  notificationCount: Generated<number>;
+  recipientId: string;
+  scheduledFor: Timestamp;
+  sentAt: Timestamp | null;
+  workspaceId: string;
+}
+
+export interface NotificationPreferences {
+  batchTypes: Generated<string[] | null>;
+  batchWindowMinutes: Generated<number | null>;
+  createdAt: Generated<Timestamp>;
+  digestTime: Generated<string | null>;
+  emailEnabled: Generated<boolean>;
+  emailFrequency: Generated<string>;
+  id: Generated<string>;
+  inAppEnabled: Generated<boolean>;
+  maxBatchSize: Generated<number | null>;
+  notificationSettings: Generated<Json>;
+  quietHoursEnabled: Generated<boolean | null>;
+  quietHoursEnd: Generated<string | null>;
+  quietHoursStart: Generated<string | null>;
+  timezone: Generated<string | null>;
+  updatedAt: Generated<Timestamp>;
+  userId: string;
+  weekendNotifications: Generated<boolean | null>;
+  workspaceId: string;
+}
+
+export interface Notifications {
+  actorId: string | null;
+  batchId: string | null;
+  context: Generated<Json>;
+  createdAt: Generated<Timestamp>;
+  deduplicationKey: string | null;
+  emailSentAt: Timestamp | null;
+  entityId: string;
+  entityType: string;
+  expiresAt: Timestamp | null;
+  groupCount: Generated<number | null>;
+  groupKey: string | null;
+  id: Generated<string>;
+  inAppDeliveredAt: Timestamp | null;
+  isBatched: Generated<boolean | null>;
+  priority: Generated<string>;
+  readAt: Timestamp | null;
+  recipientId: string;
+  status: Generated<string>;
+  type: string;
+  updatedAt: Generated<Timestamp>;
+  workspaceId: string;
+}
+
 export interface PageHistory {
   content: Json | null;
   coverPhoto: string | null;
@@ -324,6 +398,10 @@ export interface DB {
   fileTasks: FileTasks;
   groups: Groups;
   groupUsers: GroupUsers;
+  notificationAggregations: NotificationAggregations;
+  notificationBatches: NotificationBatches;
+  notificationPreferences: NotificationPreferences;
+  notifications: Notifications;
   pageHistory: PageHistory;
   pages: Pages;
   shares: Shares;

apps/server/src/database/types/entity.types.ts

@@ -18,6 +18,10 @@ import {
   AuthAccounts,
   Shares,
   FileTasks,
+  Notifications,
+  NotificationPreferences,
+  NotificationBatches,
+  NotificationAggregations,
 } from './db';
 
 // Workspace
@@ -113,3 +117,23 @@ export type UpdatableShare = Updateable<Omit<Shares, 'id'>>;
 export type FileTask = Selectable<FileTasks>;
 export type InsertableFileTask = Insertable<FileTasks>;
 export type UpdatableFileTask = Updateable<Omit<FileTasks, 'id'>>;
+
+// Notification
+export type Notification = Selectable<Notifications>;
+export type InsertableNotification = Insertable<Notifications>;
+export type UpdatableNotification = Updateable<Omit<Notifications, 'id'>>;
+
+// NotificationPreference
+export type NotificationPreference = Selectable<NotificationPreferences>;
+export type InsertableNotificationPreference = Insertable<NotificationPreferences>;
+export type UpdatableNotificationPreference = Updateable<Omit<NotificationPreferences, 'id'>>;
+
+// NotificationBatch
+export type NotificationBatch = Selectable<NotificationBatches>;
+export type InsertableNotificationBatch = Insertable<NotificationBatches>;
+export type UpdatableNotificationBatch = Updateable<Omit<NotificationBatches, 'id'>>;
+
+// NotificationAggregation
+export type NotificationAggregation = Selectable<NotificationAggregations>;
+export type InsertableNotificationAggregation = Insertable<NotificationAggregations>;
+export type UpdatableNotificationAggregation = Updateable<Omit<NotificationAggregations, 'id'>>;

apps/server/src/ws/ws.gateway.ts

@@ -19,6 +19,10 @@ import * as cookie from 'cookie';
 export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
   @WebSocketServer()
   server: Server;
+  
+  // Map to track which sockets belong to which users
+  private userSocketMap = new Map<string, Set<string>>();
+  
   constructor(
     private tokenService: TokenService,
     private spaceMemberRepo: SpaceMemberRepo,
@@ -26,7 +30,7 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
 
   async handleConnection(client: Socket, ...args: any[]): Promise<void> {
     try {
-      const cookies = cookie.parse(client.handshake.headers.cookie);
+      const cookies = cookie.parse(client.handshake.headers.cookie || '');
       const token: JwtPayload = await this.tokenService.verifyJwt(
         cookies['authToken'],
         JwtType.ACCESS,
@@ -35,18 +39,41 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
       const userId = token.sub;
       const workspaceId = token.workspaceId;
 
+      // Store user-socket mapping
+      if (!this.userSocketMap.has(userId)) {
+        this.userSocketMap.set(userId, new Set());
+      }
+      this.userSocketMap.get(userId)!.add(client.id);
+
+      // Store user info on socket for later use
+      (client as any).userId = userId;
+      (client as any).workspaceId = workspaceId;
+
       const userSpaceIds = await this.spaceMemberRepo.getUserSpaceIds(userId);
 
       const workspaceRoom = `workspace-${workspaceId}`;
+      const userRoom = `user-${userId}`;
       const spaceRooms = userSpaceIds.map((id) => this.getSpaceRoomName(id));
 
-      client.join([workspaceRoom, ...spaceRooms]);
+      client.join([workspaceRoom, userRoom, ...spaceRooms]);
     } catch (err) {
       client.emit('Unauthorized');
       client.disconnect();
     }
   }
 
+  handleDisconnect(client: Socket): void {
+    // Clean up user-socket mapping
+    const userId = (client as any).userId;
+    if (userId && this.userSocketMap.has(userId)) {
+      const userSockets = this.userSocketMap.get(userId)!;
+      userSockets.delete(client.id);
+      if (userSockets.size === 0) {
+        this.userSocketMap.delete(userId);
+      }
+    }
+  }
+
   @SubscribeMessage('message')
   handleMessage(client: Socket, data: any): void {
     const spaceEvents = [
@@ -85,4 +112,35 @@ export class WsGateway implements OnGatewayConnection, OnModuleDestroy {
   getSpaceRoomName(spaceId: string): string {
     return `space-${spaceId}`;
   }
+
+  /**
+   * Emit an event to a specific user
+   */
+  emitToUser(userId: string, event: string, data: any): void {
+    const userRoom = `user-${userId}`;
+    this.server.to(userRoom).emit(event, data);
+  }
+
+  /**
+   * Emit an event to a workspace
+   */
+  emitToWorkspace(workspaceId: string, event: string, data: any): void {
+    const workspaceRoom = `workspace-${workspaceId}`;
+    this.server.to(workspaceRoom).emit(event, data);
+  }
+
+  /**
+   * Emit an event to a space
+   */
+  emitToSpace(spaceId: string, event: string, data: any): void {
+    const spaceRoom = this.getSpaceRoomName(spaceId);
+    this.server.to(spaceRoom).emit(event, data);
+  }
+
+  /**
+   * Check if a user is currently connected
+   */
+  isUserConnected(userId: string): boolean {
+    return this.userSocketMap.has(userId) && this.userSocketMap.get(userId)!.size > 0;
+  }
 }

apps/server/src/ws/ws.module.ts

@@ -5,5 +5,6 @@ import { TokenModule } from '../core/auth/token.module';
 @Module({
   imports: [TokenModule],
   providers: [WsGateway],
+  exports: [WsGateway],
 })
 export class WsModule {}